Okay, the second attempt is working (mostly) how I intended. Essentially, if you're injured, you will need to RTB in a certain amount of time before you bleed too much to just be patched up quickly. If you go over the "bleed timer" you get a time penalty to undergo a more significant medical procedure. The last couple test nights have confirmed this to be working. However, in rewriting it to work only with how much you bleed out, instead of being largely random, it is skipping amputations, unless you are captured and treated at an enemy hospital. Friendly hospitals are either stitches/band-aid, or minor surgery.
Amputations matter because over time they can result in the retirement of your pilot. Plus, they provide some of the more humorous and colorful server messages.
I'll be trying to reintroduce the amputations and, if I can, ideally tie them to the bleed out process as well.
Overall, what we're going for is to make the injury mechanic something that you have to deal with, rather than something that just happens in the background, out of your control, reliant on randomization. The original system did have bleed time factored in, but your starting point and chance of amputation was heavily random, and you didn't know if you were starting the process already over the limit. I'd prefer to leave it in the hands of the injured pilot to return ASAP before things get worse, preventing a larger medical procedure (timeout), or to sacrifice recovery time later in the mission and tough out the sortie for some important objective.
The injury system timeouts gives us some form of time penalty during the mission that is not mission ending. I was able to make captures and deaths the same penalty, and give a different one to significant injuries. I was not able to get penalties for bailing or ditching, so the injury system will serve as our light penalty function, for those who don't make it cleanly through a sortie.
For those who want to join us, Tuesday will involve a lot of shooting each other again.