Another Amithlon convert
Your best bet is to:
-Run the oldest version of 68k UAE you can find.
(compatibility will suffer)
-And stay well away from AGA.
(ooo, I'm a poet & I didn't know it)
(see what I did there?)
-Frame skip is also your friend.
Sad to say, though I bet Amithlon runs great on your system, you'll likely need a few more horses to get the best out of 68k UAE.
Time to "pony" up a little more dough?
(a-hem)
PS
I hope none-the-less you're finding Amithlon + UAE an interesting combination...
. . . with a bit of care you can pull some interesting tricks by pointing UAE's HDD emulation @ your own sys: partition.
(some care IS required)