Dr. Jeep said:
Are submixes the way to go?
In my experience, to be avoided if possible, but not uncommon to do so.
The mere act of "bouncing" is submixing. As much today as in the older, it still has to be done from time to time. So you don't need to buy more CPU power or anything like that, it's simply just mixing with a "vintage" head.
With practice, you can do just about the same thing with 90 tracks that you can do with 24.
As advised, I would do it with caution and extremely compensative. A drum set that sounds good alone may lose it's power simply by adding on additional tracks that mask the vital frequencies that where responsible for its impact in the first place.
A popular method to try is stem mixing. Just like in movie sound mixing, you create "stems" or groups of like audio, then mix them and process them as a bounced group.
However, you can already see how limiting and time consuming it is if you have to go back and remix a stem. Or if you're not comfortable with it. Or even worse, if you erase the original tracks thinking it was final (which nothing is EVER final in audio).
So in Pro Tools, I would simply create a drum stem (with it's FX) and then make the original tracks inactive.
You can create a stereo track, assign it's buss input to whatever you choose, then route your drum FX and track outputs to that buss. Just whatever you do, avoid any type of buss processing like compression, limiting, etc. Buss compression in DAWs seems to be really weak for whatever programming limitations with the plug ins and the software itself. Unless you're dealing with something like the Impact Buss Compression Plug-In (TDM).
Of course always keeping in mind it's position and making sure than any extensions or subtractions that are made to the song are checked to inactive tracks.