Possibly more interesting than genuinely helpful:
An A1200 I recently bought had real 3.1 roms, but Wb 2.1 on the HDD...
Booted d*amn fast with tiny memory footprint + benefits of updates in the 3.1 rom. Quite cleaver I thought.
The ultimate WHDLoad setup..?
As it happens I replaced 2.1 with 3.9 & have been faffing about ever since.