Personally I'd talk more proudly about the Balti as British curry heritage cos it's a more significant innovation, it seems to me

That’s a karahi. Anyway I think British-Indian food is its own thing and doesn’t need specific dishes to be British origin.

I think these fine differences are legitimate nonetheless, though. Battered cod from a chippy, tempura cod, and portguese fried cod are absolutely different dishes despite sharing a root and sounding quite similar if you described them all to an alien

Also British people use the availability of good British-Indian food to dodge the fact that the modal level of food is quite bad.