Just a quick thought: I've read somewhere that tri-sync monitors, while supporting 15, 24 and 31Khz, don't expect resolution changes while working, just at bootup.
This may lead to malfunctioning and damage, or so they say.
Since you're going to play mostly 15Khz games (I assume), I suggest keeping the interlaced mode for the Desktop/frontend to avoid switching back and forth from 15Khz to 31Khz.