ASG TAC6 Upgrades?

Right.
So I bought an ASG TAC6 from a friend, after he got souped up his VSR-10 and hadn't a real use for this. I want to tinker with it.

Now I can already see you typing "TAC6 sucks for upgrades, its wonky as shit and the moving barrel system hates upgrades. Also it has no hop up!"

Lets get it out of the way the first thing: Its the version with the fixed hop up tuned for ~.25-.28's, bought last year, so we at least have that.

Second: I am well aware this isn't a sniper or a proper DMR, and it never will be. It doesn't need to

What I want to know from the more experienced people here is if there is anything to be done with it or something you'd reccomend.

Better fixed hop up bucking?
A longer barrel that works with the moving barrel system (if it exists)?
Theoretically making it shoot hotter by slamming back the barrel with a stronger spring (Or HPA tap it, I know...)
Mess with the outer barrel to stabilise the inner one that slams back maybe?

Maybe some magic fairy dust or some trick you know helps it?

I don't know, and I don't really have the funds or time to randomly experiment, so I wanna find some info to at least narrow what might help more and what less