Footage from life stream

Have you ever used your DSLR or mirrorless camera as live stream camera and recorded the footage separately ... and used that footage a fill in footage for your wedding video?
I am thinking about setting up my stationary camera in the middle of the isle as live stream camera and use the footage for video...
Any drawbacks?

Potential drawbacks:
My canon DSLRs don’t have a clean hdmi output - there will always be *some* info overlay. Perhaps you’re using a camera with clean output.

Physical stability of the camera/tripod in the middle of the aisle would be important, as would a safe run of the hdmi cable to the projector. Lots of movement of people in the aisle, and maybe big dresses.

Weddings are not my business, but have heard tell that some officiants are very particular about what videographers can do and where they can do it. Worth checking before you show up!