I have tried to install SNS Camen on an instance where SNS Trella is already installed.
It was very unsuccessful and ended up with:
Fatal error: Cannot redeclare sns_banner() (previously declared in C:\apps\_htdocs\trella\modules\snstrellatheme\smartcodes\banner\front\shortcode.php:2) in C:\apps\_htdocs\trella\modules\snstrellatheme\smartcodes\banner\front\shortcode.php on line 18

Is it impossible to have two themes installed at the same time and switch between them?