I think maybe the most 'obvious' fit for Sensei could be as a completely open-sourced greenlight alternative (though I think they have plans to eventually open-source the backend).

Another interesting use-case for Sensei might be for businesses who conceptually like the idea of LDK and have plans down-the-road to require a more customized lightning experience but don't have the resources to start down that path today.

They can start with Sensei (a LDK based node) and easily migrate their entire infrastructure to their future custom ldk based node without having to 'start over'. They can migrate their existing channels and funds without real downtime.

I think it's early days for Sensei and I'm confident it will find its niche as its feature set gets more developed. Stay tuned :)