Both Nova the Squirrel and Kasumi's own Indivisible are on itch.io.
https://novasquirrel.itch.io/nova-the-squirrel
https://kasumi.itch.io/indivisible
Having a rom site dedicated to just homebrews would be nice, but I think at current until there is a home for them a prevalent as like SMWCentral or ROMhacking.net if Big N lets them live, then awareness is your only option, posting about it here or on NESDev and NintendoAge. I do like the idea though. A place for homebrews where you can play the games or samples/demos of them and maybe even a marketplace to buy carts of them.