Rumba and Secure Telnet question

We are implementing secure telnet connectivity to a mainframe z/OS system using a secure port 992.  To test this, I have made the necessary telnet changes on a test mainframe system along with generating the necessary certificates in CA ACF2 on the mainframe. I sent the signing authority public certificate to the client to install in their Windows certificate key store but they have not done this yet.  However, testing from the Rumba session with port 992 and the SSL/TLS box ticked gave a successful connection to the z/OS mainframe system.

So my question is:  Does Rumba not require the certificate signing authority public key to be installed in the key store on the Windows system that is running Rumba?

It has been suggested to me that Rumba is not strict about checking for this certificate whereas other mainframe emulators are.

Additionally, I looked for a log in Rumba to be able to see what happened with the connectivity and handshake but I couldn't find one. Is there a log somewhere?

Thanks.

Paul Tomes.