There Was a Campagnolo seat post designed by engineers ,
that were not from Mount Tamalpais region.
[& didn't ride off road , more than maybe a Cross Race .. perhaps]
they at the time had a 1 bolt stepless seat post to saddle rail mech,
and learned about .. mountain bikes have a QR seat post
so they thought ... quick release seat post?, and so machined a nice Mountain bike long seatpost with a QR lever on that 1 bolt..


Now, that would be an example of a no tool seat angle adjustment..