Great news! I received the patched version, and it launched and ran fine on my A500 with my ACA500+ card and Amiga OS 3.1.4. I tested with a HAM image which it converted to 16 color like a champ. I also tested single pixel drawing, spline and text entry, and so far so good.
I will do more testing in the next day or so, but it is looking great!
Being that is only my Amiga 1200 that is showing that "single pixel brush" problem with 3.1.4 and not on my ECS machine, maybe that will give you one more clue where the problem lies