When running FMP 14 (all patches) on Mac OS X 10.9, 10.10 or 10.11, FMP apparently monitors the active modifier keys, which is great when doing things in FMP. However, it continues to monitor active modifier keys when you switch to other applications. If you are running an FMP script not as a foreground application, this causes sluggish key responses as you are typing in the current foreground application, particularly when you hit an active modifier key. The most common one is the Shift key and every time you type and have to hit Shift, there is a long delay. It goes away after the FMP script stops, but for running long scripts in the background, it makes other applications unusable. This is not a problem if you only use FMP, but most of us like to do things like read and edit mail or a web page while FMP does a long script in the background.
THIS IS A CHANGED BEHAVIOR from FMP 13. FMP 13 and before did not do this.
I hope a FMP 14 patch or maybe FMP 15 will tell FileMaker to quit monitoring active modifier keys when it is not the foreground application. That will help me be much more efficient to do other things like reading/writing emails while I wait for FMP to complete a task. Basically, this is asking FMP to play well with other applications.