Overheat is a interesting mechanic, but one thing that bothers me is this - Lets say you have a skill with a 30 second cooldown with overheat. You use it once, which starts this invisible timer and if you use it again at 29 seconds, the entire skill goes on cooldown for 30 seconds. If you waited one more second you could have used it twice. This doesnt seem right to me.
edited out initial suggestion
Just thought of another way. Going to try and explain it the best I can…Lets say its the same situation as above. Now since there are 2 charges and 30 second cooldown, another way is to have it add 15 seconds to the cooldown every use… So use it once, 15 seconds til the skill is completely cooled down, but you still have another use. So if you wait 10 seconds and use it again, you will be at 20 seconds until both are completely cooled down. If you spam them at the same time, it would be the full 30 seconds until both are cooled down. This is an even better option IMO and is almost the same as having separate cooldowns, but easier to implement i think.
