A seemingly forgotten modification is the long latch rod.
Shaun Hill (Spartan on here) can make these if you send him your old one to duplicate. They are silver steel with a hardened mushroom.
I had a .22 txhc and I put on a +14mm latch rod. It made it lovely to shoot. Slightly more work than a piston nose extension, but rather than just reducing the swept volume, it also makes a little more room for spring, so you will lose some preload with the original spring. You may or may not have to make spring adjustments.
I would definitely install a delrin guide and top hat no matter what modifications you make, and throw away the steel top hat.
Basically, it's a can of worms, great fun worms!😂😂