Grandma harness for GPU challenged?

OK I have been trying to get most of my local Qwen 3.8 27b running on my "Grandma's GPU cluster" of 2xP40. I was able to make it produce reasonably usable speeds of like up to 45 tg/s and 450 prefill with fresh context, falling to 120-ish prefill on 150K+ ctx and 12-16 tg/s. Which is usable actually if you are using it in a background, now waiting for it to finish. The problem I see is that it must be strictly one task at a time. I like and use opencode (slim) and I like an idea of orchestrator, fixer, oracle and other folks, but if you launch 2 of them at the same time, they mess with KV cache of eachother and the whole prefix caching falls apart. When there is only one process running, it nicely adds little chunks to KV cache and reply is almost instant.

The thing is - orchestrator wakes up from time to time, and starts filling cache with it's context, everything is messed up and prefill falls. I realized that the only possible way for folks like me, with limited VRAM, is to use strictly one process at a time. Yet, I like the idea of one supervisor delegating stuff to subagents.

So here is my question. Does something like that exists? I mean a harness where one supervisor delegates a task and goes off, and subagent finishes the task and writes a handoff with a complete result, and only after that superwisor somehow wakes up to do his part of a job? This way we always keep only one agent running at all time, which allows us to use prefix caching and getting reasonably fast and smooth running stuff.

I am sorry if this sounds lame, I am just an average guy, not a coder at all, I just vibecode some tools for myself. Thank you in advance for any help/ideas. Maybe something like that already exists?