@tushar sehgal Julian Millichamp said in his last maintenance video that if you scuff a new bat it needs less knocking in than if you oil it, as the fibres are softened by the piling process, and he knows a thing or two about bats!
With this in mind a bit of mallet love after an off season coat of oil can never be a bad thing. I think of it as part of the oiling process now.
When you say you over oiled a bat what was the effect of this (other than what you've already said)? Unless the willow actually rotted I don't beleive a bat has been over oiled. In fact I beleive I read somewhere WG Grace used to soak his bats in Linseed oil, if his bats survived that I highly doubt anyone would manage to over oil a bat with just a bottle of oil.
@WalkingWicket37 Julian definitely know about bats
as for me I prefer to oil -> knock -> scuff.
As for over oiling, only downsides i found were listed in my original post. Bat didn't rot but if you wipe the bat clean with paper towel multiple times over weeks and still somehow find more oil on the surface next time you pick the bat up is a sign to me that bat was over oiled, it was always greasy for almost an entire season but I didn't really notice any real issues, preferred wet weather bat
One interesting observation is at some point the bats stop absorbing oil, I think that is the saturation point for me that i have gone too far with bat and usually a wipe with a paper towel and 3-5 days of resting time means the bat is ready for knocking.