I was thinking awhile back about gas costs and harvest() and brought up how we can have a sliding fee to incentivize people calling strategy functions. It was ultimately absorbed into a proposal for revamping the treasury contracts. Borrowing @banteg’s graphics to show the planned governance contract in regards to gas:
I do think that there could be a combo function that calls harvest() and earn() and have it subsidize the caller’s gas fee by using that sliding gas fee. This way, anyone can call it and there won’t be issues with determining how much to budget for gas.