The coaches at a camp I went to used Hudl for their video. I know they were able to watch multiple cameras streamed live to the platform, but I don't know how it combined those cameras. It may not have been all available streams on one screen.
My home rink has exactly what you're looking for - multiple cameras on one screen synced in real time. But the company hasn't really taken off, and I'm not sure if they do any applications outside of this one rink. I believe the company is called MaxxSports. Maybe check them out and reach out?
I was all ready to offer feedback until I read that you already had the editing part itself figured out so... sorry, no help here. Would like to know if you find something, though.
But are they Step???I was looking at another blade manufacture that had the Clay stone,leather wipe,blade pouch and skate soakers with there logo,and thought if you can get them from Step if they sold them....It just looks sharp..