Adjust the scope and you will be fine. Or maybe I'm not understanding the issue. All guns shoot differently. I think you're making this more complicated then it needs to be.
JMO but whats up with the cut/shear being so diagonal?
Everything mounted fine when I set it up and dial in took very little. While I have the bolt action version, it took some cleaning and lube to make it smoother and when they released the side lever version, I grabbed one. Smoother, easier, less thumb wear to cock it. Usually my go-to pesting rifle for the woodchucks and raccoons we get coming up out of the creek here and so far, it's taken 6 raccoons and 11 woodchucks anywhere from 25 yards out to 60 plus.Also own or have owned any number of Hatsan springers/gas rams and the only problems I ever had with any of them were caused byme tinkering and not by Hatsan for how they made them.
I've always had good luck with Hatsan's, but sometimes you get one that's got a cattywampus that just won't fix, it can be hit or miss, good luck with the new one and Sidelevers are much better than bolts, JMO....
Not a pup but my .22 wood absolutely hates anything H&N that I’ve tried and cphp just stink as well. It does very good with jsb 18.1 and it’s variants though. I’d try different ammo first before throwing in the towel of it were I. Third flash was the charm for me. I know it gets frustrating. Good luck