More generally this fixes PLM drawing during door transitions, where the adding of PLM VRAM transfers to the $D0 table is interrupted by an NMI that processes this table.

This bug notably causes a load of garbage to be drawn where Kraid's spikes are (see screenshot) depending on CPU load when loading that room (in vanilla, the load *happens* to not trigger the issue).

Uses free space in bank $84 (15 bytes)

The screenshot shows THE BUG, not the fix