my first mods: convoy hosts

I now have two convoys, a s6 and an s8 (and an ultra fire c8 and tank007 eo9 incoming you folks are a bad influence). I’m happy with the performance of both, but nothing of mine is allowed to stay stock for long.
The s6 has a op reflector, XML u2 1b @ 2.1 amps. I’m hoping to improve it generally. I like the longer life of the 2.1amp driver, so I think I’d rather try to pull as much out of it without upping the power. I think ar coated lenses (if I don’t have already), thermal paste, and an upgrade to an XML2 would be a good way to go. Anything else?
The s6 will be my mid thrower. It has a smooth reflector, XML2 in t6 3c (which I really like) at 2.8 amp. It gets pretty warm already, but I’d like to get more out of it. Maybe stack a few 7135 to get past 3 amp, thermal paste, dedomed led and ar coated lense. Is there anything else I can do about heat?
Am I on the right path? Any other ideas? Is it worth getting a different driver, maybe something with regulated voltage? Or that is easily adjustable. Thanks, I’ll be sure to post pics when I start