The other question is: can I at least time this GC so it doesn't overlap the refresh interval and skip a frame? Because 1ms may not be significant if it lands in the middle of the 16ms period, but if it lands at the end you've just produced jitter.

So I'd think a GC designed for a gaming system would take this into account; incremental concurrent GC that can be timed to happen at the start of each each frame interval and be paused if it gets close to the end.