My left hand (righty) was injured in the military and I broke all my metacarpals other than my pinky's. I have good enough grip but kind of an awkward hold to the guitar neck.

Anyway, long story short, I find it easier to use my ring finger (rather the side of it) most of the time as opposed to using my pinky to press on the strings. I think it's compensation due to the fact my pinky is kind of on a different rotation angle than the rest of my fingers (slight).

Question is, should I continue to use my ringfinger in every scenario where I can (three string chords will usually be index and ring) or should I try to include my pinky in simple chords just to add dexterity to it and help in the long run?

I understand everyone plays differently, and it's entirely possible to adapt to a unique style of playing due to that hindrance, but I'm interested in what other viewpoints are.
Whatever works the best. Nobody really plays the same. If you want to improve the dexterity of your pinky, you could use a gripmaster, but they can get expensive ($9.95 - $24.95) if you can use your pinky, go ahead. I'm not here to tell you know, so do whatever fits both the song(s)/chord(s) and the comfort ability. Sometimes, playing weird can develop bad habits, but you can't do anything about an injured pinky other than to let it heal.