This is a license limitation
. There is a Feature request logged:
, where you can vote to increase its popularity. Note that most voted requests are developed with higher priority.
The workaround is the mentioned by you - to have a separate user with no backend access, thus the license limitation will not be reached when backend access is not needed.
Another option, depending on the functionality and permissions you have, is to log-off the user and he/she can browse the frontend as anonymous one.
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Sitefinity CMS Ideas&Feedback Portal
and vote to affect the priority of the items