I was looking at some teardowns of Cannondale's Lefty Ocho strut, which is basically an oleo strut landing gear for bikes. No direct applicability due to sizing, but one interesting design note is that, rather than using a scissor link (like most airplane oleos) or a second strut (like every sane bike), they take the top of the tubing from a typical cylinder-in-cylinder to a triangle-in-triangle, and have needle bearings along the flats, providing keying and countering rotation there. Other than taking a bit more total strut length for the same travel, and manufacturability challenges, are there downsides to this approach in our application? Examples of its use? Would a splined interface (without needle bearings) work for us?