Georg Braun's A2320-AGA project

[AmiDude]

All 3 are fully 24-bit (AGA) scandoublers.

Don't forget about the CompServ AGA ScanDoubler II.
It's also a FlickerFixer and 24-bit.

CompServ ScanDoubler II (1)

CompServ ScanDoubler II (2)

[AmiDude]

I dont own one, but it sounds like you have to physically change jumpers if you want to use 15KHz, 48KHz or 64KHz modes.

I use the CompServ ScanDoubler II with my A4000,
and don't worry...all screen displays are shown
automatically. So you don't have to change jumpers.

It could just be that these are debug registers to switch off certain features if there is a problem. Maybe under normal operation you have them all ON and you can use any mode...

Yes, they're just debug registers.