If you want to temporarily change the way explorer++ starts (new instance vs existing instance) you can change this via the command line.
-new_instance = Open new explorer++ window.
-last_instance = Open directories in the last focused explorer++ window.
I generally like to have 2 or 3 instances, and have folders open in the last explorer I have in focus. That way I don't get too many instances or too many tabs. I used to turn "Allow multiple instances" on until I had the desired number of instances, then turn it back off. Which was a bit of a pain. Now I can just have launch explorer++ with -new_instance to create each instance.
Also now you get expected behavior of "Duplicate/Move Tab to New Window" instead of the strange opening in same window you get when you disable multiple instances.
Patch for revision 163:
Demo Exe:
http://members.iinet.net.au/~bertdb/rya ... sen_1.9.7z