Wow, that is pretty noisy. I've never seen a CD-V before, didn't realise they were so bad.

Can you try a multi-frame average - a simple TemporalSoften(2,255,255) as I did - to improve things?

Also, you say that the effect of a TBC can't be seen on a static image - this is not true at all, the effect is clear. The main advantage is that wobbly vertical lines, such as the vertical white line in the centre of the pattern, become straighter. See examples here showing what a good TBC is capable of. Very useful for VHS captures, but I don't think your TBC is helping you here.