Any time you simplify and say that "best practice is" and do not qualify it, does a big disservice. I bought a Lifeline AGM battery because of a number of factors but one of them is that they do not self discharge at the same rate as a conventional wet plate led acid. I can use the master disconnect switch and leave it for the winter. The only thing left on is the Victron battery monitor so that I can check SOC and make sure it is at or very near the 100% SOC mark.
Most battery(s) can be disconnected (no parasitic loads) once they a 100% fully charged. There is no need to check water/level and a malfunctioning or poorly functioning converter poses no danger.
Knowing your batteries and what will work for them is important. Before I chose the Lifeline AGM I talked with one of their engineers and we discussed the Progressive Dynamics converter and the Morningstar solar controller. Ignorance is curable!