I made such support in KeeperFX, which uses the same rendering engine, and originally used the same VESA-based screen libs.
Now
I also renamed a lot of asm function names in sw port to match the
names from KeeperFX (see my fork mefistotelis/swars @ github).
So
if you replace the sw port routines with improved versions from
KeeperFX, changing resolution and aspect ration will be possible.