i took the plunge and went ahead and did this. i backed up ALL data first, of course.
i made a new boot stick with the later loader and went to the latest version including v3 upgrade. zero problems, no lost data, all working beautifully.
sure would like to get up to v6 though for the GUI changes. the GUI on 5.1 / 5.2 is very dated. I also do not like how in the file station when browsing, the tree strcture is odd. i had to rework some of my naming to be able to right click and copy to / move to. sort of annoying. i hope they fix that behaviour.