Great example. Compare the traction of your machine to an 8N. That engine will outlast 4-5 briggs engines easy (10K vs 2K hrs). They have an efficient gear drive as opposed to hydrostatic. Lots less maintenance and no need for gallons of hydro fluid. They have a robust 3pt hitch with an excellent PTO drive. They will drag your tractor up and down the field all day long. I really mean to be constructive, sorry if I am not sugar coating it.

I appreciate your enthusiasm. First of all, the design originates with Open Source Ecology, a sister project. I'm involved with Replimat. There's also Gridbeam, XYZ Cargo, Precious Plastic, and about a dozen other groups actively developing around the system(s).

I appreciate all your points about the sort of tractor best suited to your unique circumstances. I don't see anything about our communities designs which prevent you from constructing such a machine using our parts and techniques. I think it'd be a neat design to have among all the others which can be built this way!

For example, here is another design with it's own unique advantages and disadvantages, built using many shared components: https://wiki.opensourceecology.org/wiki/MicroTrac_v17.10

I would also note the N-series was one of the first tractors with a 3-point hitch that worked reasonably safely.