Hi, I've been fighting for a couple hours against bots trying to put concrete all over my Nauvis wood farms, is there a way to keep an area completely free of concrete ?

Not easily, right now, unfortunately. But over the holiday weekend, I plan to try and implement at least one fix.

Idea 1: A setting like the offshore pump landfill radius setting, so it won't place concrete within X tiles of an agricultural tower.
Idea 2: A new entity you can place that serves as a (possibly configurable) anti-concreep beacon.

In the meantime, you can just disable creeping via the config for Nauvis (and Gleba) if you want. Not ideal, I know, but it's an option.

at least in my game, trying to disable it for one surface causes it to stop functioning on all surfaces, so i have resorted to simply not having any sort of concrete on gleba at all for now

https://github.com/utoxin/concreep-redux/pull/42

Any progress on this? This bug makes this mod pretty much useless on gleba.

I've applied nihilistzsche's patch and uploaded it as https://mods.factorio.com/mod/concreep-redux-fixed

(and then fixed the patch to actually work)

FYI, I just posted a brand new version of this mod that actually should fix agricultural tower's area safely, so that it doesn't get creeped on. I haven't looked at your patch, so I'm not sure if I solved it the same way or not, but it worked in my local testing.