Any thoughts on how to automatically avoid rest collisions in polyphonic music?

[David Bellows]

I have a large computer music generating program that I'm creating.
One of the things it does is generate sheet music for the generated
music using Lilypond. It works really well.

When dealing with one or two voices everything's fine. But I just
added a musical style that uses three voices and collisions with rests
are occurring.

The Lilypond files are generated automatically by my software and
cannot be hand-tweaked afterwards (end users won't know how and
shouldn't be expected to do this anyway). In other words they need to
be perfect or at least good enough.

Options I've added to the software:

1. Eliminate all rests for quiet voices (which can look weird but is
kind of neat).
2. Use the \rest option.
3. Use spaces instead of rests.

Here's the thing, using any, all, or none of those options at one time
might result in a score without collisions but when I change the
instrument or just run through it again with different data there
might be collisions again. These are blunt tools that cannot be used
selectively on certain notes -- it's either all or nothing.

So what I'm wondering is if there are any other strategies people have
for automatically avoiding rest collisions and if this is the sort of
thing that might be dealt with in the future in Lilypond or if maybe
it's just too difficult a problem for Lilypond for now?

I haven't supplied an mwe (though I will if someone really wants one)
as my software generates infinitely many scores so a solution for one
score won't necessarily work for another which is why I'm seeing if
maybe there's an approach that I'm not aware of.

Thanks!