When thumbnails out number 'Max Thumb Columns', is there a setting to advance the thumbnails one by one instead of set by set?
No. Unfortunately, the thumbnail arrows always navigate through the thumbnails one page at a time (rather than one thumbnail at a time).
However, if you like, you could put forward your suggestion for a future version by posting it in the Feature Requests forum thread.
This keeps all the ideas together and ensures that they are not overlooked by the developers.
I do not know the likelihood of any suggestions being implemented in future versions but this is certainly the best place for all ideas.
Like there are more options under 'Main Image' than are explained on the Config Page :-)
There are 20 configuration options available in JuiceboxBuilder-Pro's 'Customize -> Main Image' section and all 20 are listed in the Main Image section of the Config Options page.
If you find that any configuration options are missing from the Config Options page, then please let me know what they are so that I can add them to the page. Thank you.
JuiceBox is a great product, worth every penny.
I'm glad you're getting on well with Juicebox!