Wow. This is the question of the year, right? The real question for me is/was WHAT contacts should I update and maintain?
Let’s face it. So many new users are obtaining Radio IDs from DMR-MARC, it would be impossible (or at least a PIA) to keep up to date very often. At the same time, why update every possible contact when you’ll likely never make a QSO with most of them?
So my suggestion… Update your own state, and maybe nearby states, at least once per month or whenever the mood strikes you.
I have found that this is more than frequent enough and 90% of the contacts that I make on local talkgroups are already in my radio database.
Good Luck and Happy DMR…