Unless there is a specific issue you have with the current firmware, Victron recommends you leave it alone. Simply being out of date is not a reason to update complex hardware like the Multiplus.
What I do is print my current config and manually update my inverter after it resets. Only takes a few minutes and really don’t like the part you highlighted! Victron really need to get their act together and have the GX device configure and update everything in the system. Having multiple 1990s programs required to setup and configure everything is not what I expect from a company the size of Victron! Also, I would never do a firmware update without being onsite!
So we are stuck with 20 year old hardware limitations and 20 year old look and feel software? If true, I’ll be shopping around when it’s time to upgrade my Victron equipment.