I see you use your wife as reason for the HST but has your wife ever tried a true manual tractor? Not a manual auto but a tractor. If not she might find the ranges solve the clutch issue of how to engage it slowly.
My wife use to drive a manual school bus so she is fine with manual pickup but really does great on manual tractor as the clutch is not as tricky engaging. My oldest daughter which never master manual vehicle handle my larger than you want JD rather well again due to the design of how the clutch engages and with more torque than with vehicle.
I have a Kubota
B2710 and it has limited electronics and pollution control.