Beetroot
Lil-Rokslider
You are right, the LRHS/LRTS is the closest thing ad the best chance of this happening.Br.
BR:
I apologize for not explaining the point I was trying to make more clearly. The reference to the Maven/Weaver 2-10 wasn't in the context that it's an available contender for manipulating to fit the OP; instead, it was a reference to a scope model that was available from one brand and substantially the same as a model now offered under another brand. By extension, I was pointing out that the design process to get a scope that meets the OP need not be from the ground up when the 3-12 LRHS was LOW built, hasn't been offered for some time under any brand, and would be exceedingly close to what the OP stated. Weight is a couple of ounces off, but I'd bet that an updated LRHS with a better reticle would sell and, like others, I'll point to how popular the Maven RS1.2 is.
However it doesn't meet the weight spec and I think that's one of the major sticking points with most people, otherwise they'd just buy the Maven 2.5-15.
It'll be interesting to see if this idea goes anywhere, but I know of a few people who have tried tried to do something similar to this and found it is exceedingly difficult.
Doing something like GAP did with the LRHS2, or Gun Werks with the Mark 5hd is likely the best way to go about this.