I've done this for years...and for years, I've been annoyed with config changes issues across multiple instances. I regularly have 3-6 instances open and if I want to change an option and have it stick, I have to close all the instances and re-open just one, make the change, save-config, and then re-open the rest of the instances.
Will the "-st 0" option change that behavior? With multiple instances open, will any single instance now be able to save the config? And if so, will the other instances pick up that change?