btw, as you can see testing this hack ..
ppl behind OS3.5 and OS 3.9 set the requirements of kickstart 3.1 in a dishonest way
they set kickstart 3.1 requirements on purpose to sell rom kits and to sell all the remained stock of A1200 + kick 3.1 done by Escom
sincerely I despise them now
I doubt they cared about setting 3.1 roms or a1200's, they wouldn't have received any money from that. However they would have had to double the amount of testing they did.
3.1 is necessary, quite why they blocked PCMCIA the way they did is a mystery. It should have been possible to only reject cards that couldn't be mapped (which IIRC should only have been ram cards).