TL;DR
The modifier keys can be used as keyboard shortcuts but also can be used for other actions, and sometimes they conflict. This is a suggestion for resolving some of those conflicts.What ?
The explanation might do better with an example. With a US keyboard layout, my right-[CTRL] key is on the right side of my keyboard. By default, the key to enter/leave a vehicle is right-[CTRL]. At best, I've found this annoying as my movement keys (WASD) are on the left and my other hand is operating my mouse. At worst, I've found myself in the unfortunate position of running away from biters that I probably should have left alone and hurry into my car while firing on enemies behind me, only to realize that I could not aim, move and get in my car at the same time.To remedy this, I changed the enter/leave vehicle key to left-[CTRL] which is next to WASD and that worked wonderfully. But that introduced another issue: when [CTRL]-clicking to move items/inventories, when I release left-[CTRL] I find myself unintentionally entering a nearby car or worse, train that's just leaving.
I realized then, that if there was a way for the game to recognize that an action had been completed using a key (left-[CTRL] in this case, the action being having attempted to transfer items to/from an inventory) that it should then not use that same key for any other shortcuts until it is depressed and subsequently repressed.
