going back down to OS 3.1 from 3.5

[tonyvdb]

Is it easy to go back down to OS 3.1 from 3.5 without doing a total reinstal and is SFS suported with 3.1?

[amigagr]

for going back to 3.1 i think that you need at least to overwrite the system files with the ones of 3.1 so the effort is quite the same. i would going to a clean installation. sfs works with 3.1 but you have to patch the scsi.device with nsdpatch, a method similar with the one of 3.5 :-)
in any case, make a backup of your current system disk...