Thanks for the information, everyone! Keep it coming!

I did some median-of-five experimentation yesterday with excellent results, but I think I'm going to try doing a capture without the Leitch DPS-290 before continuing down that path. If it's similar in quality to the others, then I'm going to redo all five.

The biggest problem I had yesterday was in temporally-aligning the captures to one another. I was able to get 3/6 to line up well. (Surprisingly, those were the only ones I did back-to-back; e.g., capture, rewind, capture, rewind, etc.) Considering that it works via frame-freezing, I think the Leitch DPS-290 is to blame.

I'll post an update tonight.