I thought I would others know of my experience using presets imported from AT with a blueboard used for changing them. First as others have noted there are definitely changes to overall output levels when just going from AT4 to AT5 using the same AT4 preset. So I dutifully edited my imported presets to lower output levels and saved (overwrote if necessary) the imported AT4 preset. This creates a new preset with an extension .at5p.
As I then tried to switch presets with the blueboard, I noticed that the changes I had just made did not take. I would get the preset with the output level wrong. The fix is that you have to reassign the new .at5p preset to the blueboard otherwise it loads the imported .at4p version which was the original one.
Since the only difference in the name of the preset is the extension this difference cannot be seen in the midi assignment window as the extension is not displayed. In other words the midi assignment keeps track of the extension internally even though the UI does not display it.