I completely agree with retired1af that the option to avoid reformatting the /home partition when upgrading VL is crucial.
On this point, I suspect that if I were to install lyx, etm (and perhaps other programs that are hard or time-consuming to reinstall) as non-root rather than root (root install is normally the easiest) and followed my usual practice of not formatting /home when upgrading to the next version of VL, I could avoid reinstalling those programs as well. That would be very nice. Heck, I could even then install and work with a new beta version pretty easily. I don't know where the cut-off should be. Some programs, like python, qtpy, setuptools, etc should probably always be root. I guess this is something that each user will need to decide for him/herself.