The web access control bar can be moved to the right hand side instead of the left. However you have to grab the handle and drag it all across the screen for this to happen. This is far from obvious so many users might not find this feature.
Upstream has resolved this by adding a small place holder on the opposite side once you grab the control bar handle for a while. That should work well enough for us. Upstream commit: https://github.com/novnc/noVNC/commit/bbc1648 We need to make sure it matches our style though.
Tested this and works great on on: Win 10 - Chrome 77, IE 11, Edge 18 macOS 10.14 - Safari 13 Also changed the hint colour to match our Thinlinc style.
Also tested this on iOS 13 in Safari 13 just in case. It looks good, both the hint and the ThinLinc color.