Push to pass, in my opinion, is better than KERS. They are both similar but push to pass adds an extra layer for strategy. You only have a limited amount so it's up to the driver how and when to use it during the race.
Your issue isn't with KERS but with the regulations which govern how it's used.
Here's my proposal:
- Double amount allowed on KERS unit
- Retain amount allowed gained per lap from recoevery
- Allow extra to be carried over from one lap to next if unused
So (I can't remember the figures here so I'm going to use simplified ones) - an example
Current storage on KERS = 100
Future maximum on KERS = 200
Driver X ends lap with 30 remaining -> Add 100 allowed gained per lap = 130 available for next lap. If they don't use all of that, what's left gets added to 100 for that lap.
SO, this allows for strategy in that if a driver can end one lap with much more spare than other driver, they have more KERS available to try and overtake. If they use more, they don't.
This would add strategy in that drivers would have to try and force a driver in front to use more KERS one lap to enable increase chance to overtake using extra KERS the following lap.
Defending drivers would have to try and use minimum amount of KERS per lap to ensure they have equal or more KERS than attacking driver for following lap
Obviously, the extra element is that if teams want maximum amount of storage available, they would have to develop cars capable of taking it.
IE - If they couldn't build a car that would allow the full 200, they would be limited to a full maximum KERS of say 160...
The only downside is that say a driver got comfortably out in front, they could balance their KERS unit to enable them to strageically use KERS around a pit-stop to ensure they were either well out in front when they came out, or could use it to get tyres up to temp quickly...