Wanted to try Rocket Arena one more time? Why noone ever puts up any rocket arena servers? Blah?
KTX devs need FEEDBACK on this, click on the title to read the rest...
Now is your chance. KTX has been modified so that it supports RA mode by simple command. To enable RA in KTX, you just need to type:
/cmd arena
And start fragging. You can play any map you wish using RA mode, but every time you change map you'll need to re-enable RA with that command given earlier. The servers currently supporting RA mode in KTX are:

Easy.quakeworld.dk:28501-28506

Wg.slackers.dk:27501-27503

Qw.suomicom.fi:28001-28008

Troopers.fi:28001-28006
Of course any properly configured server using the very latest KTX supports this mode, so bother server admins to update if you want to have it on certain servers.
EDIT:
To discuss about how RA should be implemented or the options missing or other things like that, please use KTX website forums, there is a special section for Rocket Arena:
http://qw-dev.net/projects/3/boards(Yes, you need to have an account to be able to post, but it will be shared between QWTV/MVDSV/KTX and other projects websites)
Also, make sure to create bug reports or features requests to the same website if you tested RA with KTX and feels that need be:
http://qw-dev.net/projects/3/issues(You can submit trackers as anonymous ie no account required, but an account is recommanded)
Have fun!