Use the pi as a mobile base, and take it to the field so you can use over radio ?Aye apologies I'm no sure which caster you're discussing, but I was using Romano Mains last year until it disappeared
Though it's back on, I've not been using rtk correction so far this year. I don't have mobile reception on a fair bit of the ground up here in the hills, and sbas dgps is more than good enough for pass to pass fert and even the odd bit of spraying
I have built my own base using a raspberry pi, but the poor phone reception issue hasn't encouraged me to upload the data to Rtk2go. I have looked into using xbee radios, but the transmission power we're allowed severely limits the effective range, and that's before you stick some volcanic rock between base and receiver