@Anakirob - Not sure. But I ended up amending my draw routines for the A500 after having it work perfectly on my A1200 040/25. I tried a couple of approaches, but the faster Amiga was definitely faster.
One thing I did try was only blitting one off-screen tile per pixel scroll. So, if I scrolled at 2 pixels per frame, I would have 16 chances to blit as many 32px tiles as I needed. I could blit about 4 per frame without any slowdown. A diagonal scroll would require 19 tiles for a 320x256 screen (10 across, 8 down, and one for the corner). Easily done in 5 frames
