Lots of variables, but your string already looks great!! Getting the utmost usually comes,at the expense of trial and error. I have always been a fan of matched ports. I do sometimes run large valves and barrel ports, but restrict the tp with success.
I did find that when everything gets large, sometimes the only way to drop velocity is reg pressure. I did a regged .177 that had somewhere around .160 matched ports. The only way I could get the velocity down to a usable 900fps with those ports was to drop the regulator pressure down to something like 70bar. So, yes, you can go too far but to push the envelope in search of max performance, usually results in going too far at some point.
I have sold off most of my regged guns, but really like what you are doing!! Keep the info coming and best of luck in your endeavors!!