No, by setupcomplete only, or installing it in audit mode and capture the install to a wim. https://forums.mydigitallife.net/posts/1895887 added to the 26H1 Updates Overview!
Hi, back in January I used Feedback Hub to report the issue where Windows Update couldn't retrieve 28000.1450. But in the February Patch Tuesday they decided to fully release 26H1, and Windows Update can download the February update. Maybe my feedback influenced this
Check again WU worked fine on 2800001575. On my test pc, running 28000.1641 it thinks it already is installed. Working too on 28000.1641
That can be but it is a preview on catalog and optional on WU update, when you want to do a full ISO, go ahead.
Only if you're enrolled in the insider program in the Canary Channel, check in WU > Windows Insider Programme.