A system where your currently being trained skill can have a buff to training speed while you actively use or interact with associated modules or features.
For Example, I begin to train Blasters 5, while this is being trained if I fly a ship fit with blasters and fire on anything I trigger a short duration training speed buff that slightly increases the speed at which that specific skill is trained, similar to the remap system.
This would allow players to feel like they are contributing to their skill training by actively playing the game and using the corresponding things without making it OP and without making any other feature redundant.
Some skills would need to be grouped where there is no direct one to one relationship with an in game activity, or where its very diverse, for example reprocessing skills would gain the buff when ever a player reprocessed any modules or ore.
Or skill related to trade might trigger the buff when player auctions get bought or new buy orders are placed.
The time component of the buff, i.e. how long your little speed boost lasts would be tuned to the specific thing so for example shooting some missiles might net you a 5 minute boost of 1 or 2% while something thats a lot less common like reprocessing might net you a longer time.
The Values would need to be tuned and balanced, it’s pointless trying to think of concepts that eve players wont abuse because we abuse everything, this should not be a valid reason for not doing something, if it was we would never get anything new.
The benefits of a system like this are all player side, players may be encouraged to perform actions they might normally not do, pvp pilots who or off training some hualing stuff and want to speed it along might spend some time doing hauling missions to trigger their buff.
Miners who might want some new guns could be encouraged to spend some time killing rats, or shooting players to help their’s along.
And given the bonuses and percentages are not stupid, a lot of people will probably just let this buff trigger naturally.