This all could have been done in 3 simple steps, i am creating a video as we speak, no need for any autounatend.xml stuff.
That upgrade path should be possible, maybe it needs a license switch to normal Enterprise 2021 LTSC and then upgrading to Enterprise 2024 LTSC and next switching back to IoT Enterprise 2024 LTSC by Key. Or try this tool to perform the upgrade directly: UpgradeMatrix.xml FiX Tool (Very Beta)
Convert your IoT Enterprise LTSC 2021 to desktop edition (non-IoT LTSC 2021), download Enterprise LTSC 2024 ISO with a same UI language you have in your current OS. Unpack the ISO, for instance, via WinRAR or maybe just mount it, run setup.exe, follow on-screen guides and wait for magic to happen. You may be lucky If yes, switch the fresh OS back to IoT edition. But I have no idea if you can make this all if your PC doesn’t meet Win 11 requirements. IMHO, better to make a clean installation.
The EP apllicability list mentions EnterpriseS (= 2024 LTSC) but it is not sure it will get updates when applied on it. Code: <assemblyIdentity name="Microsoft-Windows-CoreCountrySpecificEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-CoreEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-CoreNEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-EnterpriseEvalEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-EnterpriseGEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-EnterpriseSEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-EnterpriseSEvalEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-EnterpriseSNEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-EnterpriseSNEvalEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-ProfessionalEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-ProfessionalNEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-ServerAzureStackHCICorEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-ServerDatacenterCorEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-ServerDatacenterEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-ServerDatacenterEvalCorEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-ServerDatacenterEvalEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-ServerDatacenterNanoEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-ServerStandardCorEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-ServerStandardEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-ServerStandardEvalCorEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-ServerStandardEvalEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-ServerTurbineCorEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-ServerTurbineEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-UtilityVMEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-WinPE-Package" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-WinVOSEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> <assemblyIdentity name="Microsoft-Windows-WNCEdition" version="10.0.26100.1" processorArchitecture="amd64" language="neutral" buildType="release" publicKeyToken="31bf3856ad364e35" /> The 22H2 applicability list does not list (IoT)EnterpriseS, so all can happen, although that would break the purpose of running a LTSC version.
I definitely won't manually mess up with it unless I have 100% confirmation that future Windows Updates will still be offered also for IoT
This enablement package is still the dev channel one which is a few months old now. The displayName in the update.mum says "Feature Enablement for Dev Channel Preview Update (KB5054156)" and the version is 26100.5503.1.1, so I think MS will/should release a new enablement package (which may not support LTSC).
The current one has EnterpriseS in the applicability list* and there should be a new one for the retail channel, we will know when it appears. * https://forums.mydigitallife.net/posts/1888353
I was also in doubt if there will be future updates in LTSC after 25h2 hehe since LTSC doesn't officially have 25h2
No. 24H2 is the last LTSC release. There won't be an official 25H2 release by Microsoft. Maybe next year they'll release 26H2 LTSC. But not this year.
LTSC = ~every 3 year a new one, usually. 2016 LTSB 2019 LTSC 2021 LTSC 2024 LTSC Expected is 2027 LTSC
I wouldn't do it manually or you may break future Windows Updates for it. Wait for official GA. If it will be offered also for LTSC or IoT, otherwise keep it as is.