I don't think changing the DHF to a different flavor is going to solve everything. You say you like the DHF but it's too slow and soft. When you say soft, have you tried raising the PSI a couple of numbers? You like the handling of the DHF more than an XC/trail oriented tire like the Regolith? Hmmm. Dissector not enough grip. OK I think I have enough info 
I'm not sure if the new Nevegal will provide more grip than the Dissector; I have not tried either yet but I'm guessing they are pretty similar in overall grip. The Nevegal is not going to provide DHF levels of grip I don't think. It's worth a try. It also sounds like you should try the DHRII on the front. If you like the DHF's handling but you want a bit more speed (and yes I know some people say it's slower), try that tire. I don't think the DHRII is slower on the front at all. Just because the top lugs are horizontal doesn't mean by definition it's slower --- the top lugs are significantly shorter than the DHF's --- it's hard to see that in a picture, you have to compare them side to side up close in person. You'd then see that the DHRII is about 1/2 way to being a semi-slick compared to the DHF's huge center lugs. DHRII rolls fast, trust me. Handling good, braking good. It does get more sketchy at the limit but I think it's worth trying on the front for sure. Nevegal will probably remind you more of the Dissector, for better or worse (they are probably both great tires but maybe not for what you are doing).
I'm not sure if the new Nevegal will provide more grip than the Dissector; I have not tried either yet but I'm guessing they are pretty similar in overall grip. The Nevegal is not going to provide DHF levels of grip I don't think. It's worth a try. It also sounds like you should try the DHRII on the front. If you like the DHF's handling but you want a bit more speed (and yes I know some people say it's slower), try that tire. I don't think the DHRII is slower on the front at all. Just because the top lugs are horizontal doesn't mean by definition it's slower --- the top lugs are significantly shorter than the DHF's --- it's hard to see that in a picture, you have to compare them side to side up close in person. You'd then see that the DHRII is about 1/2 way to being a semi-slick compared to the DHF's huge center lugs. DHRII rolls fast, trust me. Handling good, braking good. It does get more sketchy at the limit but I think it's worth trying on the front for sure. Nevegal will probably remind you more of the Dissector, for better or worse (they are probably both great tires but maybe not for what you are doing).