Thanks for you inputs. I'll give a quick update of where I got up to.
Without going into too much detail we use AS to produce steel design drawings (less detail than shop drawings) with the intent of producing shop drawings in the future. Our current customized setup for AS2020 yields 30% productivity gains (conservative estimate). There is still some manual drafting over the top of AS output, but it's manageable.
So this is what happened:
1. I copied my databases back to default locations then installed AS2022 (safe option if .xml is ignored).
2. Ran AS2022 to make sure the install was working fine. Ran the Migration Tool to copy customization across.
3. Migration log showed no errors. Great! (or so I thought).
4. Opened AS2020 on one screen, AS2022 on another, then started to copy all customization comparing differences along the way. This took about 4 hours. Easy enough but tedious process. Did I get everything? Who knows.
5. First thing I noticed that was wrong was that my template .dwt was not saved to AS2022 file format. It remained AS2020...
6. I opened up all .dwt/dwgs and then saved them manually noting that OOTB AS files were already AS2022 file format.
7. I finished setting up tool palettes etc. and created a simple model to test cameras with custom user drawing styles.
8. No cameras would register drawings to the model. Big problem.
9. Tried default cameras with default drawing style but same situation. Big problem.
10. A force update on them crashes AS every time.
11. I copied backup databases to default location to run OOTB setup to see if (8 & 9) above were caused by customization. Perhaps I missed something but also remembered that any "author text" in databases that I set didn't get copied across so this didn't help my cause.
12. AS wouldn't load after this so I decided to do a reinstall as an easy option. Big problem.
13. The uninstall didn't remove all the directories so I manually deleted them. Big problem.
14. I ran AS2022 setup again but it didn't install any files to C:\ProgramData\Autodesk\Advance Steel 2022 !
15. Checked forums/knowledgebase articles for solution.
16. Tried a few different things but after 3 or 4 attempts I became more confused as to why AS doesn't allow repair or reinstalls as an option as that would have saved me the last 2 hours of my time.
17. I found an article that Autodesk has removed repair/reinstall options from version 2022 and onwards... err, why?
18. AS2020 is still working and runs great with the customizations. We should just keep using that! It has a few bugs but at least it can be reinstalled...
So I found out peoples frustrations with the process. It was a waste of 8 hours of my time. If only Autodesk put as much effort into products other than Revit that would be nice.