If I wanted to turn a reverb into a mono reverb, then what is the best technique to do so?
 
Not all plugin verbs come with mono versions.  It seems the only ones that do so are from Waves.  In SPLAT, the technique should be rather simple, by clicking the Interleave button to mono mode.  This, I figure, would basically drive one mono signal of audio into both L/R channels of the stereo reverb.  The outputs of the reverb plugin would be identical and be "summed" into the track's mono channel again.  Without a coding change, like what Waves does perhaps, then this is how I think it would work?  But couldn't any introduced phase differences caused by reverb reflections, etc. cause problems?
 
And what if the DAW does not allow a stereo track to be changed to mono?  Ableton Live is like this.  With that in mind, take Eventide's Blackhole for instance.  From the BH manual: "Blackhole can be used as Mono-In Mono-Out, Mono-In Stereo-Out, or Stereo-In Stereo-Out."  There are no controls on BH to do this, so it must be done automatically based on a mono vs. stereo track.  But like I said, Ableton Live will always keep a track stereo unless it's initially configured as mono by having a mono input, i.e. from a mono input from an interface.
 
The only way I can think of to guarantee a straight-mono reverb is to use a processor like ISOL8, BX_Solo, or another utility to solo/force only the mids.  The processor would be placed after the reverb in the chain.
 
Sorry for this question.  I guess I'm over-thinking it, but I'm really in a quandary over stereo processing these days.  I listen and analyze professionally mastered material, in the form of a 24-bit, undithered .wav file, and I hear stereo content all over the place, including the bass frequencies...yet it has perfect mono compatibility and sounds ridiculously clean!

You can just use a stereo plugin. Most of the ones that make sounds wider will also make them mono. If you're worried about mono compatibility I wouldn:t worry about your reverb though. I rarely find that reverb is the problem. I would try just cutting the bottom of the reverb and see if that cleans things up instead of making it mono. Although mono reverbs can sound good too.

Sonar's Channel Tools

Change the interleave on the track or buss to mono?

If your signal in is mono, then skip the first step, which is: put a stereo-in-mid-only-out plug-in in the insert chain.  Now both channels out of this plug-in will be an identical mix-down of stereo to mono.
 
If your verb is stereo (which it seems to be, thus your question), insert that next.  Both channels have the same input, but a stereo reverb will most likely treat L and R differently.  You want mono out with no chance of nasty side effects of mixing stereo down to mono, right?  So ...
 
Follow the verb with another inserted plug-in that will throw away one channel and use the other one as output (equal levels) on both L and R.  In other words: L-in -> L-out and L-in -> R-out.
 
My plug-in of choice for steps 1 and 3 is MUtility, a freebie from MeldaProduction.