For the sake of vocabulary, I think you're talking about "training recovery". There is short term recovery, like the time you need between sets, but you mentioned supercompensation so you're talking about something more like:
I just did a bunch of compound barbell lifts, how long until my body
will be stronger because of the exercise?
You can get some pretty safe-bet answers, and largely this dictates your training level. If you can recover in 24-48 hours, you're in the novice stage. If you need a weekly program to cause (and recover from) supercompensation, you're an intermediate. Len Kravitz wrote a nice overview.
I'm not aware of any studies, other than specific looks into modifiers (sphingosine 1-phosphate , STAT3 inhibitors, nitric oxide, alcoholism, etc). Hormones, rest, protein, hydration, existing illness, and age all come into play (plus many other elements).
There are a lot of factors involved to answer your question. Your max squat will cause much less damage to your body than the max squat of a high level power lifter. You will probably be fully recovered in 48 hours, and that power lifter might spend a week doing 50% of his or her max.
Is it theoretically possible for a muscle group to complete the
recovery and the supercompensation phase in as little as several
hours, or overnight?
Perhaps, for someone completely de-conditioned who can exert such small amounts of force on their bodies that the recovery time is small. But in practical terms: no.
Are there physical symptoms to look out for?
Ultimately you can only measure it with strength. If you can lift more, you're stronger. I've had days where I feel terrible, and even fought little kinked up injuries the whole time in the gym, only to hit my PR's.
The practical way I know to find the answer for an individual is to put them on a good training program. Max out your novice gains (where you can add weight every couple of days because you can recover that fast), then move onto the intermediate level.
Another thing to consider too is that this goes beyond muscles. Your neurology changes, as does your connective tissue. Adding all that up, then looking at the vast spread of training differences, it's easy to see that although there are general guidelines when you want to get specific you need to look at everyone individually.
