I have been working recently with Karajorma, trying to add multiplayer respawn points that are definable in FRED, which have some other "special" qualities. In the particular instance we've been working with, there's a huge asteroid that has some hollow areas in it, and it would be nice if we could spawn ships in them. Now, of course the bounding-box calculations for normal respawning prohibits this.
Our idea was to add an object flag which marked the object (probably a waypoint) as a known-safe respawn point, even if the bounding boxes say otherwise. This is trivial. However, we're then stuck with the not-so-ideal solution that you can have ships spawning on top of each other.
We've really only seen one solution: Draw a line between how big "small" and "large" objects are, and check only for collisions with "small" objects. It gets worse here though, because then you have the situation where you get shoved into the middle of a "large" object when it tries to solve a collision with a "small" object. The way we've seen around this is to find a new respawn point if the one you chose has a "small" object at it, and if you can't find an empty one, then you've gotta do what you gotta do. There's a couple things to do about it, but they're not the point of this topic.
Our question is, does the way I've described sound too hacky to you? Both Karajorma and I are a bit nervous with making an arbitrary decision about what's "small" and what's not, but we're having a hard time seeing another way.