We have removed the navigator bar from the shinyproxy app. We did this by cloning the github repository and editing a few of the html files within the resources directory. To accomplish what you want, you would need to modify app.html file.
<!-- navigation bar -->
<!-- <div th:replace="../fragments/navbar :: navbar"></div> -->
This simply is commenting out the navbar. This will impact all applications that you launch so this may not meet your requirements. This would require logic based on a configuration in the application.yml which should enabled in the future.
Once you do this, you need to use maven to rebuild the shinyproxy jar file on your local server.
mvn -U clean install
We're pretty happy that Open Analytics has made this an open source project. It is letting us extend the solution to work for our company.