iManager relies on Java. Perhaps a different design is needed, one that works without a browser or has more consistent behavior with many more browsers, and without Java. Or perhaps a better product is needed, one with a user interface that improves navigation. Java is being deprecated by more and more organizations. Perhaps a programming design should begin without a runtime environment and interpreter.
Make the next generation iManager use the engine that was used for the GroupWise 2014 Administration Console. That GroupWise 2014 web based administration console is outstanding, it looks like a program running within the browser.
With Oracle trying to find it's way in the open-source market, this is a good time to move iManager away from needing a Java script. Even Google and Apple are finding ways to let loose the Oracle juggernaut. Remember the disaster named Console One...?
The guts of iManager are fine, but it definitely needs some interface work, some improvements to its error handling, and some of the teams responsible for plugins have been lax in their updating and fit-and-finish.