I can't seem to change any configs within Minecraft to fix only having one smelter at a time in a backpack's upgrade slot. I want to have an auto smelter and auto smoker, but the options for configuring the mod are greyed out, everything is up to date. Did you remove the option in a later patch or is there a way I can configure that in another file? and if so how? I am running on Forge 47.2.0 on AT launcher.
If you need any more information feel free to ask.

You are using some mod for the configuration gui (I am guessing configured) because there's no gui included by default with forge and I am not adding any either. So you will need to direct this question to them. I have no idea what are the conditions for the gui to be configurable vs not and what I could have done to make it disappear (and I don't recall making any real changes to config other than maybe adding one or two options recently).

And configs as always can be changed in configuration files (sophisticatedbackpacks-server.toml for your case)

I looked in that file multiple times, and I still don't see anywhere I can change the limit of smelter upgrades on a backpack. On a previous versions I had no issues, but now, when I try and make a new backpack, it says the limit of smelters is one. The only configurations I found for the mod were changing the vanilla loot tables and enabling/disabling their crafting recipes.

sounds like you are not looking into server configs but common ones. Search for that file name I shared above and there's maxUpgradesPerStorage in there

I used Everything file Explorer to look for the file, it didn't occur to me to look in my /Game/saves instead of /Game/config. But I did get it all fixed and I will see if I can remove the GUI mod that blocks it. Thanks for you help 👍