Start9 looks for a bitcoin core based repo in the current marketplace it is set to. Since Dojo is in Community Marketplace and Bitcoin Core is in the Official Marketplace they cannot "see" eachother.

We do not specify that Knots can be used in our manifest for Dojo, so I cannot say exactly how this happens.

Dojo will not work with Knots from a code standpoint as the projects are fundamentally at odds with eachother.