FWIW -- My version of the Comanche was installed to Community folder from A2A. In case it makes a difference, I actually installed it to a different folder on my C drive and am using Addon Linker to send it to the Community folder, which I also moved to a different C drive folder location from MSFS default. I too have FG=off / V-Synch=on, but I was still getting 000 hobbs hours after I transferred all of my data files over from 2020, and I checked that I had all of them. My Work folder screenshot looks similar to what brendanv1 posted, with the livery named dat and dat.f files, but after the first time that I loaded into the Comanche MSFS2024 created it's own blank name .dat and .dat.f files. I was last flying a custom livery in 2020 (N8298P) in MSFS 2020. I have always had persistency by livery checked and active.
I was able to get the 2020 hobbs hours to transfer over and show up in 2024 by copying the N8298P_Custom_Registration.dat and .dat.f files off onto my desktop. Then I renamed them to match the MSFS created blank ones of .dat and .dat.f. I deleted the .dat and .dat.f files that MSFS created in the Work folder, and then moved my renamed .dat and .dat.f files from the desktop back into the Work folder. Then going back into MSFS 2024 and loading the Comanche custom livery into a flight, my 2020 accumulated hobbs hours were there along with my last fuel levels etc, etc. Great! HOWEVER -- Now those same hours and all other saved state elements show up regardless of which livery of the Comanche that I load into. I tried moving my renamed ones back out of the Work folder and re-loading into the Comanche. Once again, 000 hobbs hours and after closing the sim it had re-created it's own .dat and .dat.f files. Deleting those and moving my renamed ones back in then caused the hobbs hours etc. from MSFS 2020 to come back (but again same ones show regardless of livery chosen). So it seems like MSFS 2024 is only reading whatever the no-name .dat/.dat.f files contain on load, and also if they aren't present it re-creates it's own. It appears (in my instance) to not try and match the selected livery name to any data files containing that livery name.
The other interesting thing in my case is that MSFS 2024 see's the custom livery loaded from the Community folder as another Variant of the Comache, not just an additional livery as in MSFS 2020. Next to it is the "buy more liveries" button, so I guess that new "feature" in MSFS 2024 maybe explains that treatment.
Hopefully some of that is helpful. Thanks for looking into it all!

- msfs2024 work.png (47.88 KiB) Viewed 145 times