I was wondering, if I use the GB interceptor as a capture card, how do I have to classify my runs. Is it GB emu ?

I'd say anytime you're not using the actual cart it can be classified as emu.

@PoorMansCouch If you're playing on a flashcart or real cart, and you're playing on SGB1/2 or actual game boy, then it'll be marked it as non-emulator.

(btw I had to google what a GB Interceptor is...must be a new thing. but it seems like it just captures from hardware/cart so yeah, non-emulator run is what you submitted)