I’d feel much better if, like you say, there wasn’t the lingering worry that my summer mesh jacket would ride up in a crash. It’s on the longer side, which is good, but it’s a much more pliable and easily-deformed material than my leather jacket, for instance.
Honestly, I’m just not really willing to sacrifice choice of gear to make sure that pants and jacket have matching zips. It really is a stupid thing, but I’m not surprised at all that standardization hasn’t happened. In the end, I’m not going to buy Shift pants to match my jacket, though I might buy a Dainese jacket someday to match my Air Drake pants.
As with leather work, I don’t know of any tailors or custom garment manufacturers that know how to deal with the usually absent issue of durability in a crash. Even if I could find somebody to make a matching zip system, I’m not sure I could trust it in the event that I go down.
Ultimately, I solve this problem via back protector. Mine straps firmly around the waist and shoulders and will not go anywhere if I go down, even if my jacket does ride up.