Currently, safe mode merely stops plugins and anything in /boot/extra from installing.
I would like to see that renamed to Safe Mode - No Plugins
I would like to see another option added Safe Mode - No Plugins / VMs / Dockers
Dockers / VMs (VMs in particular) can cause issues with stability as a whole if the hardware / firmware / bios is not operating properly, and it can be a PITA to diagnose running those additional features.
Also, I think it would be wise to have the system when running in Safe Mode to never autostart the array, as if there is bad enough corruption of an array drive / cache drive, it can really cause havoc during start and/or prevent starting altogether. Far to often on the forums we tell people to manually edit disk.cfg and disable autostart.
Additionally, I think that when using the GUI mode from the startup you should also have all the safe modes available within it too.