I use a tubing cutter and I take my time. I "can" cut one in less than a minute but it will roll the tube inward and I will need a few twists of the reamer to get the inside diameter back to the original size. So, I do 1/8 to 1/4 turns on the knobs at the most and rotate around the tube a couple of time, repeat.
It is hard to clean up teeth marks on small short pieces, so I stay away from bandsaws or circular saw blades. Angle grinder or use the lathe and a file edge as a parting tool.
Waiting to see other's response.