I tested the Fenix 7 versions, Epix 2, FR255 versions and FR955; all have 256 kB available for datafields now. Only the Epix 2 had that at release.
Especially for the FR255 versions this is very surprising and I wonder whether it is correct or just a bug. The normal FR245 had only 32 kB and the FR245m had only 64 kB available (which was later upgraded to 128 kB).
256 kB is really a lot of memory to produce code for. I am not complaining, but I wonder what kind of datafield-functionality needs this amount of memory. Personally I rather had seen the possibility of having 3 datafeilds active in one profile, like the FR735xt was able to.
