Playing with fewer players than seats feels uncommon enough to avoid any support for that in the level format.
Most levels need different terrain for different number of players. Existing culture is to build several independent maps with the same name, one per player count, and always pick the map for the exact count. With the different terrain, the map will look clearly different.
Situations where we play with fewer:
- No variant of that map exists for the player count. We pick the variant of the map for the next higher available count. We accept an imbalanced match over pausing the session to create the missing variant. This is rare.
- Race maps that have only a single hatch and a single exit. Everybody spawns a few lix from that hatch. I didn't think of this, then Rubix started creating race maps, and the existing format/rules haven't choked on that concept.
The concern is case 1, what to do in the rare case where we lack the map for the exact player count. My feeling is to warn before play. To allow as much as possible without offering any support in editor/format, I'd prefer to prune/merge the seats with a hardcoded algorithm. I'm tending towards algorithm #3 from two posts up, it's the most lenient.
For case 2, race maps, I'm considering to support hatches/exits that go on every seat. This special case seems worth it. For every hatch/exit, you can choose either exactly one seat or every seat. Doesn't feel 100 % nice -- why support this and then not arbitrary subset of seats.
-- Simon