OMP provides a significant amount of structure to the work. That costs some tokens in terms of the system prompt. When I use these systems, I balance the return of the extra guidance in the system prompt with the cost of the context. You've talked about how much context it takes, but you haven't talked about any difference in behavior.

omp offers some nice tools, like /shake, to manage context efficiently and offset some of that consumption.

Not sure about your point with command keys. OMP has all kinds of shortcuts and is highly configurable. It seems very unlikely that you cannot achieve what you're looking for in OMP in terms of shortcuts. Specifics would be immensely helpful here.

And yeah, you'll need to run your inference engine separately from your harness, for the same reason the web server and the web browser are different applications.