If your riding terrain doesn't demand much suspension action, going to a rigid fork isn't a terrible idea. If the rigid fork dimensions are similar to the Reba dimensions, the handling dynamics of your bike shouldn't be significantly effected. Spend a little time poking around on some of the MTB-focused discussion forums, and you will find a subset of riders who are happily using fully-rigid bikes. If you look at the gravel racing scene, you can find some riders on fully-rigid MTBs. Gravel riding/racing isn't always smooth dirt roads. It really comes down to understanding what the compromises are, and whether the benefits are worth it to you. Personally, I think a super-light fully-rigid MTB would be a lot of fun. The first MTB I owned (1990) did not come with a suspension fork, and I rode it on pretty much all of the same roads and trails I ride my current MTB.