Where is the number of plays stored? (technical)

Somehow I missed that interpretation the first time around. So part 2 is significantly easier. We can literally write calculated EQs straight into the dynamic data partition and the player will then know about them.

I don't suppose you found any strings corresponding to the EQ preset names? It'd be useful to be able to change that too.

So that just leaves the tricky part of analysing the response and calculating what is needed to correct it.

(And the actual implementation...)