Out of curiosity I searched the forum user list and found some current beta testers who are not Xojo Pro:
Björn Eiríksson (einhugur)
Thom McGrath (boy is his new picture different from his old one!)
William Koperwhats
Mattias Sandström
Tino Gruse
Oliver Schellhammer
Chris Mott
Carlos Antonio Cratere Hernández
Some of those have never been active on the forum or have very few posts. After the first four, none of the names were familiar.
IIRC I got 516 hits on my search for beta (BTW one Member’s last name is Beta but he is not a beta tester!) and some were on deleted members.
A LOT of the Xojo Pro beta testers have 5 posts or less, and the majority of those have 0. Wish I had counted them! 
- karen