Hi @sebastian-lieschke_5424 ,
Thanks for the request; this is something that is close to requesting a new feed type, so I'll use that rubric to decide.
As we wrote in that link, new feeds can be very time-consuming to research, develop, document, maintain, etc. Like with all software, even estimating the cost is costly - so we can't really even begin the initial research until there's sufficient demand or market opportunity to justify the possible investment.
To be honest, I don't see there being much demand or any market opportunity for this. Time will tell, and maybe someone will comment on this in the future. But for now this seems really niche.
That being said - I took a quick look at the document you linked, and I don't see API docs (i.e. those missing endpoints you mentioned). Maybe it's something as simple as a basic JSON document. Maybe it's an absurdly complex and undocumented API.
However, if you can figure how the API works, and it turns out to be something like a simple JSON/XML index file.... and you can prototype/fake that using a static file inside of a ProGet Asset Directory... then we can likely implement that quite easily.
I know that's how RPM and Helm Chart feeds got started long ago :)
Alex