I had some time yesterday to compulsively re-edit everything completed so far and to incorporate some you your suggestions. In particular, the repeat of the melodic middle part did get some additional melody lines and orchestration changes.
And I did add a bit more percussion and remix it a bit. The first percussion that was in there was mostly a delayed, distorted, auto-panned kit from Heavocity's Master Ensembles. I re-edited a lot of that and added some Apocalypse kit (mostly rim hits except for the toms mid way through and the snare that is mixed in more often).
It still weighs in at only 2:14, and I agree that it could probably be extended, but that sounds like a lot of work ;)
So it is still just a draft in A-B-B-A form (yeah, it could get bigger if I played around with voicing/instrumentation and did something like A-B-B-A-B-B-C .... like a pop song, eh.. verse, chorus, verse, chorus, bridge.. lol).
Anyway, I think I got the gist of some of the suggestions and have incorporated some of them, and now have a template for a much longer piece if I ever get especially ambitious, I think?
https://soundcloud.com/gregory-barnhill/huh-42-by-my-robot-orchestra