I would but the throttle return springs are mounted on the heat shield.

When I first got em I had no heat shield and couldnt figure out for the life of me where the return springs mounted.

If I had the skill I could make a replacement one that would maybe fit, in fact I could probably do that with enough time but I need new extractors to run the su's anyway, there's like 2/4mm gap between the fuel bowls and #1 & #4 exhaust primaries

Heat shield does just that, always good to have. I say modify it it you have to but keep it or make a custom one. Just my 2 cents worth!

Here in NZ we have (had?) two styles of 4-1 extractors available.
1. "twin carb" - centre two pipes (ie 2&3) go over the two outers (1&4). To suit twin sidedrafts (Webers/Delortos etc)
2. "Single carb" - centre two pipes go under the outers. Suit std single carb manifold.

I've used both. Same pipe diametre. Don't think the single carb style would flow quite as well due to them needing to 'tuck' down a little tighter where they exit the head. Having said that I'd say they run well with GX set-up.