I'd tried 24H2 from 23H2 about 6-7 months ago but there were too many unfinished areas to persist with (mostly little popup windows complaining that such 'n such is changed on 24H2). My felicitations to those who chose to be early martyrs - you've done a great job.
Just retried this weekend (full image backup of the 23H2 installation was done first) using the simple Upgrade without programmes/setting losses technique.. There seems to be none of those earlier issues now. Everything, with one exception, works as it did on the 23H2 installation. I'm using Open Shell and even that said: "Reconfiguring for 24H2" - and it did so in a few seconds, now works fine. The one exception is the loss of a direct network icon to one of two other PC's on my home network, although their mapped drives are there and using manually typed network addresses finds them instantly. The SMB 1.0/CIFS boxes are all turned on, and this configuration worked flawlessly in 23H2.
There is just the usual issues with doing this, despite the statement that all programmes/settings are retained. Fonts are not retained, network settings (especially network access) are defaulted to MS' own safety zone (ie. nobody can do anything unless all the boxes are re-ticked) ... and so on. Happened going from 22H2 to 23H2 as well. Winaero Tweaker helps a bit here.
My question now is: what actual difference and improvements am I meant to see ? So far, I may as well still be on 23H2, with the exception of the direct network icons.