OP, if you’re using tubes could you not setup your wheels tubeless (ghetto if need be). Then use the tyres you have been, without the weight of the tubes.
I think Stevede had a point about weights too – I’ve used tubeless 2.35 High Roller’s (900g) on the back for years. Not many problems at all, when I have it was because they were too soft for the terrain.
I’ve recently put a 2.3 HRII tr exo on, as per previous answer, sliced it second time out. It weighs 830g, too light I think, and it looks like I’ll be taking it off – a shame too, as I think the tread works better than a normal HR.
Edit: Conversely, I’ve used standard, single ply, 2.35 Minion DHF’s, setup tubeless on the front for years. They only weigh about 700g and last ages! I live and ride everywhere in the Lakes too.