So if I was looking to use the onboard mic with the Flash XDR (say for some event work or for getting broll), I would assume that I can just go out of the RCA outs of the camera and go directly into the XLR-ins of the XDR using a RCA-to-XLR cable?

Seeing that there is also an audio drift adjustment on the XDR, this looks like a viable option (although I don't think there would be a drift recording this way ... someone correct me if I'm wrong)

Dear Michael,

As you are aware, the RCA outputs of the XL H1 are unbalanced while the XLR inputs on the Flash XDR are balanced.

You could experiment with a simple adapter and it may work.

An unbalanced to balanced adapter (which includes a transformer) would be my first choice.

To the best of my knowledge, we have not yet tested the Flash XDR by providing an unbalanced input into the balanced XLR inputs.

The levels should be fine.