I previously mentioned that this mod was adding duplicate wooden tool recipes, well there are still many other recipes that I also found.
The following vanilla items have duplicate recipes added by rustic itself:
-sticks
-all colors of beds
-sign
-oak chest
-crafting table
-pressure plates
however, it seems these are different in that I am actually able to force disable them via crafttweaker

I've looked through all of Rustic's recipe code and jsons, and I haven't found anything related to these recipes. I have found out that certain mods can cause recipes to be added with Rustic as the resource domain for some reason, which is why it says the recipes come from Rustic. So far the only mod I've been able to pin down that does this is primalcore, but I didn't see that listed in the crash log you posted in the other issue, so I'm not sure which mod is doing it in this case.
If you can find out which mod is responsible, I might be able to help, though. I'd suggest using the tried and true method of repeatedly removing half your mods until the recipes disappear, then doing the same thing with the last mods you removed until you've found the culprit.

I know it might sound like I'm just trying to shift the blame to someone else, but I swear I'm not adding these recipes. All of Rustic's json recipes can be found here, and all of the hardcoded recipes can be found in this file, if you want to see for yourself.

I'm able to reproduce this using only JEI and Rustic installed and no other mods at all.

Crafting Table example here:

And here's my modlist just for proof:

Here's an imgur album with a few more conflict examples:

https://imgur.com/a/U22fQ

Here's my version info:
MC 1.12.2 Forge 14.23.2.2615
Rustic 0.4.8
JEI 1.12.2-4.8.5.147

I was looking through your repo and I couldn't figure out where these recipes were possibly getting added, since you pointed out here and here are the only places where recipes are being created.

So, I decided to do some exploring into the jar file from Curseforge itself, and here's what I found under \assets\rustic\recipes:

I deleted a couple of the recipes, like the crafting table, and sure enough the duplicated recipe was gone.

I'm not sure how those recipes got added in there, but this was from a fresh download off of Curse, so there wasn't any tampering involved.

I plan on releasing an update to solve this issue and more within a day or two.

The update was just released.