Thanks for your question and sorry about the delay. As of right now you are able to send an email to alert a technician that a session is waiting for them, but not an SMS. You can set this in "Settings" within a specific Technician Group in the Admin Center and by scrolling down to "No Technician Available."
Would SMS be a big improvement over an email for your needs? We've looked into it in the past and it's certainly something we can revisit.
In the interim, I setup a mail forwarding rule at our mail server level. When I receieve the e-mail notification , the mail server forwards e-mails when the Sender contains: @logmeinrescue.com and Subject contains: New Rescue. I have it forward the e-mail to my cell via it's text address email@example.com