Ive heard that the petpet lab maps are only usable if you have the secret laboratory maps. True? or No True?
Yeah petpet lab ray only becomes accessible after redeeming all of the secret lab map pieces. IMO petpet lab is dumb though, because you can't really do anything with a zapped petpet.
You can only have the Petpet lab after Secret Lab, yes. And you can't pound (but you can transfer) or sell labbed petpets; only good side to them (besides aesthetics) is potential avatars, e.g. a zapped Meowclops.