When in SRST/CCME hybrid mode, the wan connection is down any way. So the SIP connection to the router will be down. You will have to default to H323 pots dial peers to send calls to PSTN. Not sure if i answered your question.
When the wan connection is up, you can use SIPT from CM to the gateway. When wan is down and phones go to SRST mode, obviously your calls will have to default to H323 pots dial-peers and force calls through the local PRI. Unless you have SIPT provider local to each remote site, you will never use a SIP voip dial-peer under CME/SRST mode.
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.