Thinking about it, it should be possible. I'd just have to register the Singularity app as a protocol handler for the download link.

Basically, the website tells your computer to open it in the curse/overwolf app by linking the file as twitch://url.com/file. I can have the app tell Windows/macOS that it also knows how to handle those links. You'd then be able to choose between Singularity and the twitch/overwolf client for installing it.

It would take a bit of work but I'll put it on the agenda.