The problem with adding a group box on the right is it then gets calculated in the columns as you have found and adjusts the rest of the window design.
I ended up putting definition fields underneath what ever field they are trying to explain the behavior of. Its a shame though that Ivanti removed string -1 fields ability to auto size based on the text contained as this was allowing for quite a clean UI but gave flexibility when you needed to explain a fields use.
In respect to populating these fields with the information, I chose to create a category object in System called Definitions, personally i opted to make it a html string attribute so i could have the option of linking to documents fairly simply.
My design was to then link the category object to whichever object I wanted to be selectable from once for each definition required on the window.
Add the definitions to the window, use a template to set fixed values that should always be displayed and update the shortcuts the analysts use so they use the template, once included in the template the definition selection field can be hidden on the window.
Now the painful bit, I have just added the related html attribute to the window and all was well, until upgrade to 2016.4 and the related attribute stops displaying its information until after a save. a workaround could be to create extra string attributes for the display of the information and then use window copy rules to populate the text from the definition field. The regression has been logged with Ivanti and accepted as a bug so hopefully will be fixed soon.
I will definitely try your procedure. I really appreciate it!
Thanks a bunch!