Install multiple copies of ATP LibreOffice on GNU+Linux

I currently have two versions of LO installed, the 6.2.8 apt and the current version snap.

The first one I can’t update anymore, I have an old release of ubuntu, 16.04, the repositories are no longer supported and I don’t know Ubuntu enough to move without causing damage.
It is however a version that I don’t want to lose because it is much faster than 7.4 especially with large files.

The 7.4 snap, which I use as a software developer in starbasic, I see that it doesn’t correctly support the shell function (which I need) and sometimes it gives me problems debugging macros (unexplained crashes, etc.) and it’s quite slow (I have an I5 with 8GB of ram)
However it has the advantage of updating automatically without problems

I would then like to install the latest atp version, by downloading the debian installation package available here Download LibreOffice | LibreOffice - Free Office Suite - Based on OpenOffice - Compatible with Microsoft but without touching the old 6.2.8 in any way.

Here it - The Document Foundation Wiki I see a tutorial for install multiple copies of LO

I ask you if the tutorial is complete enough, and in addition to saving the entire 6.2.8 profile, what else do I need to save in order not to lose anything from this previous version, including the possibility of running it in parallel with the new version.

Thanks for every contribution