i heard that one type of covering cannot stick to the other, i dont remember which one, is this the case???
im constructing a few scratch built planes to mess around with and dont feel like spending a bunch on covering (cause i will have no idea if they will fly and fly well), and seeing as i will have all christmas break to work on them it wont bother me if it takes longer/looks bad useing towerkote.

Tower/Econokote over Monokote. Low temp on top of the high temp.

I've never found one covering that won't work with another. As far as different temps go, most coverings shrink better in one direction than they do the other, so it's really a crap-shoot.

I mix coverings often and have never ruined anything, Go for it!