As mentioned in Script Runners documentation, sometimes it only makes sense to name the JQL functions the same between Power Scripts and Script Runner (or any other add-on with JQL functions) so these clashes can happen. The way Jira works is the first add-on to register a JQL function when Jira starts wins. And, since Jira loads the plugins in alphabetical order and Power Scripts comes before Script Runner in the alphabet, Power Scripts tends to win.
What you may then experience is some filters or dashboards throwing an error because the JQL function is expecting to be in Power Scripts format instead of Script Runners. However, the way we built the JQL functions in the apps make this a very simple problem to solve.
We built every single JQL function as a separate module in the app. This means, that should there be any clashes that you need to resolve, you can go to the specific module and disable the JQL function, assuming that is what you want to do.
Those modules will stay disabled even after you restart Jira. This means that when Jira is restarted Power Scripts will not attempt to register the specific JQL function and the name will stay available for the next app in the list to register it, thus no clash.
Now wasn’t that nice of us?