The only type of fee-smoothing scheme that is feasible is to smooth an entirely
separate category of fees that are made mandatory. For example, you could
achieve the economic impact of inflation by having a fixed value*time based fee
that goes to timelocked anyone-can-spend outputs in the coinbase to push the
fee forward to other miners.
I'm not sure what the implications would be of charging coins for moving based on their value times how long since they last moved would be (I *think* that's what you're suggesting). It isn't obviously bad, but feels weird to me.
That said, a scheme which would work would be to have a fixed minimum fee of satoshis/vbyte which is required to be repaid out by the miner into a pool and they get back a fixed fraction of what was in that pool. The pool could simply be a rolling coin which keeps the balance. That's still a bit ugly but doesn't lessen block size significantly, is fairly coherent, and is a soft fork. It's the best emergency measure I'm aware of.