This is great stuff! As a side note, I wonder if anyone has created a HAM viewer that runs in the browser? I remember HAM flickering by necessity and being amazed by 4096 colors on-screen at once. There was a certain quality of HAM images on the Amiga that made them instantly identifiable.
HAM doesn't flicker. The issue with HAM is that you're limited in terms of abrupt colour changes.
It's straightforward to convert HAM to PNG etc.
It would have sometimes been used together with interlaced mode to double the number of lines and that did flicker.