You can login as tester or tester1 on the demo board https://myforum.nz/demo with password 123456 and take a look at the admin section, if you like what you see contact me and I can install & configure the forum for you.

some other examples of Yabb

https://linux4u.nz/forum/
https://securehost.nz/forum/

not my install but a very nice board with lot's of users
https://www.aussiecampovenforum.com/cgi-bin/yabb2/YaBB.pl

& of course the YaBB developers site
https://yabbforumsoftware.com/cgi-bin/yabb2/YaBB.pl