Any precautions to be taken when updating 2.79b .blend files to v.2.81?

I am going to update all my project .blend files from v.279b to v2.81. The project files are mainly architectural model which contains many sub-assemblies / sub-sub-assemblies / parts files in the forms of linked proxies and linked groups resemble the typical mechanical CAD assembly files.

The files will be updated by opening and saving all the files in Blender 2.81. What kind of precautions should be taken to prevent files become un-openable after conversion?

Should I update all the lowest level part files first and then sub-sub-assembly and then sub-assembly and finally the topmost level assembly file? Or simply it does not matter which files are updated first?

I haven’t had any problems as yet converting from 2.79b to 2.81!
Only with textures that contain alpha mask, need some work and somethings in cycles will not work in eeVee…
But… be aware that it will place things that were in layers into new collections and some will be hidden from the viewport, but it is an easy fix…and you can always move them in and out of collections or change their visibility.

also, Groups turn to Collections, Duplis are no more…

Thank you for the advise.