rom bios allocation max - what's needed to make it work?

[Torinde]

I try various combinations of:

• rom bios minimum size
• rom bios allocation max

And I consistently get full 64K BIOS starting at F0000 (checking via MSD).
If I don't disable Cassette ROM BASIC - sometimes I get an error "Callback area spans 64KB segment".
If I select rom bios allocation max = 12 (or less) I get an error "Callback area spans 64KB segment" (with APM and PnP disabled).

It seems DOSBox BIOS data should be able to fit inside 8K (when not using ROM BASIC), but I can't get even close.

Does "DYN" (in debugger BIOS MEM) mean that DOSBox will dynamically choose its location? I don't observe that so far - you can have lower "allocation max" when you disable stuff that's in the way (e.g. BASIC, PnP), but you can't move any of the positions - neither DYN nor FIX ones. And then I don't see any effect from "minimum size"?

Any advice?