Oracle also distributes a couple of testing tools for Java Access Bridge. The tools are called Java Ferret and Java Monkey, and seeing if those tools can spy or map your application should be one of the first things you can experiment with.
The tools were downloaded and installed with previous versions of JAB, I am not sure how it is currently distributed by Oracle since JAB now comes pre-installed, you may have to do a bit of a google search.
If Java Ferret/Monkey cannot interface with your element than it would indicate that your elements have not been built in an accessible way - rather than any fault with the Blue Prism implementation of JAB. If that is the case than Surface Automation is the only solution available to you.