I've been making some parts out of 1/2" aluminum rod which get turned down
to 0.200 for 3/8" of an inch, and the end chopped off.

they need to look pretty and the fillet has to not be gouged out.

What I've been doing is

throw a 1 foot rod in the sherline lathe, support the other end with a
steady rest with brass feet and lots of oil.

in 0.025 passes neck the rod down to almost 0.200. Deepr cuts seem to
cause the rod chatter and "walk" around working the steady rest loose.

move back over to the 1/2 side and face off the wavy shoulder off in a few
passes.

an uninterrupted finishing pass along the 0.200 side then out along the
faced off side

turn the rod OD to exactly 0.500

face off the 0.200 side so it's exactly 0.375 long

cut the part off with a parting blade, final length is about 7/8ths

slide steady rest towards chuck and repeat.

Is this what anybody else would do? I have no machinist pals to drop by
and chat about stuff like this with.