Heads up!
With the updates and changes to the mod api with 2.1 there's a good chance that Personal Transformer will stop working if you update Factorio to 2.1. It'll probably be a while before I'm able to make updates to PT any time soon as I just moved and am still getting the new house figured out, not to mention learning the new API changes.
As always, post your bugs here and I'll get to them as soon as I can. And if anyone has any ideas for changes with the new API, let me know as well!

EDIT: Good news. I want to see about making the edits myself, but all that needs to be updated is the Info.Json to say 2.1. your mod works without any edits

Hey, I enjoy your mod alot (a nice QoL item) I dont have experience modding for factorio, but I do on other games. I noticed in the change log for Asphalt Roads Patched matched the error codes I got when I tried to simply change version numbers. I thought it may be enlightening to you to help update your wonderful mod.

- Summary of code changes needed for 2.1 compatability:
  - Recipes: category: string -> categories: {string}
  - Tile transition code had to be updated to match vanilla code again.

It seems the way recipes were organized changed. again. im not familiar with factorio modding, but this bit of information may help you patch your mod faster.

Hey @Pikachar, I see you have all the code on GitHub, but I'm not sure if you are open to accept any contributions. I don't mind spending some time working on upgrading the mod to 2.1, @Ariexe already mentioned it could be a simple change. Thanks!

I am open to contributions on github. I even try to credit people in the main page. I just want this mod to be the best it can be. I've been sick all week and have been trying to catch up on work and what-not. If you've got upgrades/changes/etc and know what to do, make the changes and make a Pull Request on the github page. I'll try to review it and approve it when I can.