Sometimes it takes a considerable amount of time to evaluate groovy back-end script. For instance when data is loaded from remote resource by a reactive parameter.
As for now, the plugin hang the webpage till data is loaded. The behavior is not very user friendly when it takes more than 2 seconds to evaluate the script.

Ideally, the page should not hang and all, and loading animation should be shown for parameter being evaluated.
Alternatively, the plugin can show a 'loading' splash screen if the evaluation s gone for too long.

PS I can contribute to the code if some directions are given: 1) ideas on how desired behaviour can be implemented 2) where to start searching for places in code where the desired improvement can be implemented 3) how to test and commit the resulting code.