If someone wants to write a patch for it, I will seriously consider adding it. I believe that safely adding 2FA would be very time-consuming, so I'm not willing to do it myself or direct Slickage to do it.

2FA is going to be implemented in EpochTalk. I suppose we'll all be able to use it once the forum software has been replaced:

https://github.com/slickage/epochtalk/blob/master/app/templates/login.html