When I first asked this question I was only attracted by the video mentioned above and I was not very practical with the UR system. For example, I thought that the URCap could have been interactive in some way during the execution of the program. Maybe the same video was misleading.
Later I have better understood this system (cf. Execute distinct scripts within a URCap) and now I don’t think any longer that a full screen mode could be very useful.
On the other hand, I like the proposal of @jubeira. It can be hard to fill everything in a single page of something about 600x500 px. The possibility of switching the whole interface between several preconfigured setups would be useful. Especially if it could be enabled on custom button click.
Nonetheless I also understand that this is not a priority, since a workaround already exists.
Alessandro Tondo @qbrobotics