in fact, since last August, the structure between MESS and BSNES is more similar than it was before: BSNES rendering design was so elegant and simple that I modified MESS to work the same way, rendering one mode after the other and calling a common set of functions for each mode.
the main difference is that BSNES handles directly each single pixel (making "easier" to implement effects like offset-per-tile) while MESS does not (and hence OPT is still missing).
That said, moving the whole video emulation to a device in order to better sync things is probably a good idea... just don't count on me to do it (in the short term) because I keep being a bit busy with real life
