Reference implementation does not and will not support this with high probability.
However, farmer is also a library and there are even lower-level components below it that can be re-purposed. So it is 100% possible to build a custom farmer that has one network connection and connects to local sub-farmers to make them share data with each other and collect results of their work. Kind of like local independent farming pool where you don’t have to trust or rely on any third-party.
I don’t think we have a capacity to build that any time soon, all spare time I spend on Space Acres, but it is definitely possible and would likely qualify for Contribution Contest too!