EDIT: links to Release Version with updated DPC+ driver (June 24, 2017) and the Tournament Edition (blog entry on July 19, 2015).
While working on Frantic, I wondered if the sprite driver could handle even more sprites if it didn't have a playfield to update. That lead to an experiment with 50 sprites, which was successful.
50 sprite experiment (not all are visible due to flicker)
50 is a handy number for the game Asteroids. It's progression of 1 Large -> 2 Medium -> 4 S
Existing Harmony and Harmony Encore can be upgraded to support the 64k and 128k CDFJ+. I haven't announced this because currently no homebrews are available that require this, and I don't expect any demand unless any such homebrews are released.
However, there is one 64k game in development that I am aware of, possibly two, but nothing larger than 64k right now, and the timeline for these isn't clear. Further, it is possible that the 256k and 512k will never be used so upgrading a Ha