Damage Per Round
I find it strange that you can have games where you lose 5 health from barely beating someone, but the next round have a very unlucky game resulting in over 32 damage. I think that having the damage you take equal twice the round gives a very steady timer for most players, it lets you mathmatially figure out if you can afford to lose rather than rolling dice or watching someone you thought you would take out be left at 1 HP. Not sure why Riot doesn't talk to the community more about these ideas but my guess is they have found TFT to be "popular enough" that they are just going to keep it the way it is, hopefully not, hopefully they bring community players on board and message more than just a few streamers and pros with their thoughts.
Here's hoping!