It feels like you're falling into the age old pitfall of trying to achieve a goal by changing all of the variables at the same time. That rarely ever works out.
First up, you have a linear comp. That's great for your neighbors at the range, but it's going to do nothing to reduce recoil. In fact, linear comps actually increase felt recoil. The compensation portion is related to flat shooting at the sacrifice of increased recoil. So, you're fighting against yourself there. You'd be better off with a simple birdcage or, if you don't care about your neighbors, an actual brake. BUT, on an 8" barrel, that brake is going to spit some fire. If you like the linear comp, just be aware that it's acting against your goal. But that's ok.
After that, focus on one component at a time. Maybe focus on the buffer and try different options and see what happens while keeping the same spring. If you can't get what you want, change to the spring. Just focus on one thing at a time.