Hey Cooper, welcome to the site.
I think bouncing sync over to the green line is possible, but probably not easy.
I know the PS1 and PS2 have sync on green output, and some monitors require processing that to csync, but I haven’t come across anything going the other way round.
The type of sync is usually a factor with the display you’re using.
If you could give us an idea of what your end goal is, maybe some other, more tech savvy, users can speak to those particular aims.
The Retro Setup thread will attest to the various gear problems overcome by various members.
I think a few VGA monitors accept RGsB, but should also accept RGBHV, which is probably easier to achieve.
I’ve never made any cables, and most of what I learnt about sync comes from a few online resources.
https://www.retrorgb.com/sync.html
Hope that helps. 