A lot of the weight of the dhf is in the size of the rubber knobs. In exo casing it’s not wildly heavy (I think the 2.5x650b is just over 900g) – so to save weight you are going to lose some rubber.
You might find instead of saving weight you get something with a better rolling resistance.
On the back I’d replace the 2.3 dhf with something that still brakes well but has less resistance. Normally I run an aggressor in the summer and dhr2 from October – March / April time.
I was going to try a dissector this year as it’s meant to roll faster / generally be better than the aggressor – but then I saw a slaughter 2.6 grid in the Spec tyre sale for £12 so I’m going to give that a go (if it fits through the back of my bike).
I’ve wanged a 2.6” Forekaster on the back of my new ht – said to be ‘aggressive xc’. Hoping just to run it all year round (dhf 2.5” front in summer / magic mary 2.6” front the rest of the year). It coped with slop last weekend on some
Bridleways much better than I expected – will be interesting to see how it rolls in the summer. It’s pretty light for a 2.6” tyre so I’ve stuck a Rimpact in there just in case.