Although I can't remember ever changing these settings at all, I looked anyway just to try it out. There is no 'reset to default' button on that pane, so how do you do that?
On a side note, this is really getting frustrating. I use remote X11 connections every day for almost everything I do. This is not only impacting my life, but my wallet too and I really wish that Apple would get this fixed and leave it fixed. It's doubly upsetting that the fixes exist 'in the wild' which means that someone has done the work for them if they could only pay attention. I guess I'm done with my morning rant, I'll try and figure out how to load the 'insecure' X11 again.