I’d be interested to hear how you get on with this.
I spent 18 months playing around with Watec cameras, using Raspberry Pis and USB video capture dongles to hunt for meteors. The project in an abeyance at the moment, and to be honest I’m not sure the USB video capture hardware was up to the job. Essentially, your video signal is mostly black, and as I understood it, the cheap capture dongles were turning the gain up way too high so we were mostly recording noise. Any real structure was totally saturated. As I understand it, better video capture hardware has brightness controls that let you adjust these things.
Having had that experience, I would be wary of putting anything in my signal chain between the camera and my digitiser. I’d want to know exactly what the video time inserter is doing. If it’s passing the analogue signal through, maybe it’ll be fine. If it’s digitising the signal and then converting back to analogue, I suspect it’ll be a disaster! 🙂