For 6061,
3/4x.110” wall weighs about .35lbs per foot.
3/4x.125” wall weighs about .37lbs per foot.
1”x.0625” wall weighs about .3lbs per foot.
1”x.125” wall weighs about .52lbs per foot.
To get carbon with enough strength in a lighter weight, you’re using hardware, spacers, and other components and dimensions of other components that increase weight. UNLESS, you’re deep in this and have significant experience with carbon or money to pay someone who does.
Geek off the street isn’t going to win on weight. You can make a quieter stick, probably.
Want to cut weight? Have someone weld you sticks out of aluminum components.
I can get a 18” step spacing at 1.2-1.3lbs per stick double sticks no moving components for a 250lb fella using every hunt for 4 seasons with no sign of fatigue.
If we built the same sticks with .75x.110, it would easily hold my weight(200lbs). I’d probably go with 17” step spacing. Sticks would be at or less than a pound.
But - I’m rooting for ya! Let us know what you come up with.
I’d build a prototype with readily available thicker wall carbon tubing until you get the concept down, then spring for the expensive thinner wall stuff.