Wow, I properly nerded out when I saw this mod! Yes please! I can't wait to try it, thank you so much for coming up with this :-D
I know nothing about modding, so I'm throwing these ideas at you without regard for how possible or hard it is to pull off, but I hope you'll find these considerations of use:
1) Semi-automation in the sense that the harvester will go off and harvest any selected ores. So it doesn't have to find them, you just use some menu akin to the deconstruction planner and the harvester/s go get it. Preferably, you set a target for each harvester. Or, you can make new harvesters and link them to a refinery, and set the target from the refinery, which dictates what all linked harvesters do? In my head each refinery has a "train track" like platform, onto which you place a harvester from your inventory. This links the harvester to the refinery, but it then drives off freely. Or, you can place it loose on the ground, to be driven manually.
2) Like trains, a flip switch for automatic vs manual, so you can drive them if you want.
3) A filter for which ores to gather, in case you get overlapping patches and you just want certain types.
4) Compatibility for Bobs, Angels and Space mods, if it's not already? I'm playing Space with a friend right now, and this mod would be AMAZING for that, especially if semi-automated! I'm trying to clear a planet of all ores right now and this would make the logistical challenge so much more fun and convenient!