I would like to have a go with windows 11, but I am told by the system compatibility checker that my system isn't supported. Is there a way?
Yes, You can, but according to the information available so far, only to version 22000.xxx. Further updates are at least currently blocked. But think very hard about whether You still need this version, because it's really much worse and also has many problems if to compare with current Windows 10, which You can still use for about 5 years and also get regular security updates without any problems.
Fix the ISO (option 2) and you can install 22000.xxx on all systems on which 10 could run too. Simple hotfixes will be installed without any problems, only new feature updates/upgrades (aka next major new release) will need some attention.