Truss parts are already on Thingiverse (I didn't design them):
Lego Technic 42146 new parts frames by Michael535 on Thingiverse: https://www.thingiverse.com/thing:6113344
The material is SUNLU 1.75mm PLA "Pure Yellow" from Amazon. I'm very happy with the material.
The original CAD design for the track treads I designed are on Onshape.com but I didn't upload the STL to a sharable site like Thingiverse. I'll create an account the next time I have something to share and upload then.
Yes, tried incorporating the pin’s snap-fit feature into the printed part but the results were poor. Altered the design to use a light press-fit on the pins and have them do the snap-fit retention. Worked really well. I may go back and sand off the protruding studs at some point…
Update: I printed and assembled 8 sections for a new boom. The original sections are redistributed to the mast and jib. I need to re-string the entire model as the provided strings are all too short. I’ll post pictures soon.