Batch splitting ProRes into equal-length segments I routinely have to take ProRes footage and break it up into twenty minute segments of both ProRes and h.264. The computer I'm currently using to do this does has Premiere but not FCP. Any ideas on how to automate this as much as possible?

It's important that the edits are exact down to the frame; I've had problems in the past using Compressor 3.5 for this process where consecutive clips would not play seamlessly from one to the next.
I would use ffmpeg. Just write a sript in any scripting language you prefer and tell ffmpeg to encode new files depending on the total duration of the source file and let it only encode a certain amount of time.
You can completely automate this sort of workflow with ffmpeg.