That's the spirit. It's great when you can find someone with knowledge eager to try various things to make a faster Bat. There is no ryhme or reason to tinker with a moped and I think that's what intriged me to get involved in this hobby and see what the limits are on my project Bat. I like to think of it as Hot Rodding for poor people. It gets in your blood and evenually goes to your heart.
You don't know how happy I am for you that you found a 2 cycle mechanic that loves to tinker. Some of my friends are mechanics and they got involed with mopeds as a way to unwind and have fun in the shop after hours. One guy has about a 20 Bat junkyard for parts and has 4 Bats that run. (Don't ask for parts because we need them ourselves) One Bat looks like a drag bike after the frame chopping was done. Although you have to get a running start and jump on this Bat it will give you a ride in the 60's as it slowly winds up on a flat road. Another one if his Bats is a black 76 VA fully restored to it's original condition.
They've thrown around ideas such as stroker packages, bigger bore packages, and radical port timings. Some have come to fruit while others are still in the dream column.
Take care and happy tinkering.