Extra Life is pretty underdeveloped, it could have something more to it to make it worth that 25 points…
1; Change the colour of skill menu and/or have an icon next to the multiplier to demonstrate that you still have the extra life, and will go back to normal when you use up the first hit. It’s really annoying to keep track of it, especially when you lightly tap the wall and you can’t tell if it counted as a hit or not.
2; Add an XP multiplier if you keep the extra life when you bank the skill, maybe 1.5x… There’s pretty much no reward for keeping the second hit, so there isn’t much of a reason to be careful even when you still have the extra hit.