Could maybe make them emit a sound when you're healing, to help give away where you're at. But either way, I don't personally think it's a big deal. TTT isn't really supposed to really be some super fast paced nonstop action based gamemode. Rounds take time, and as long as they aren't intentionally avoiding conflict the entire round, I don't see the problem in waiting a few extra moments. It's not like they can just do it forever.
If anything I could possibly add an ability to some like you said, but to balance it, it could heal you to the health amount it allows instantly but at the cost of all the charges, so a one time use. Only in overtime.
If anything I could possibly add an ability to some like you said, but to balance it, it could heal you to the health amount it allows instantly but at the cost of all the charges, so a one time use. Only in overtime.