I would add 3 major maintenance operations often forgotten and that can lead (personal experience ) to desastrous if not lethal situations:
. connectors and lugs : regular connections tightening is key; vibrations (natural or related to human activity), heating/cooling throughout the year or within the day cause loosening of screws and nuts (unless they are of spring type); once a year fastening campaign is a very good practice
. thermography: overheating in some parts of the panelboard are common; they can be due to loosening connections (see above), or simply repeated overloads or simply aging of components (in particular electronics like load shedders, regulations,..) but also simple contactors coils; again regular campaigns are useful to “spot hotspots”, but they must be carried out when power usage is at its peak, not during summer breaks…
. filters : some panelboards, in particular embedding control (PLCs, relays, and the like) are ventilated or air-conditioned to prevent excessive heating (and thus switching and then damage) of components ; they have filters to prevent dust from entering he panel and worsening the situation; however filters are subject to clogging, and depending on dust conditions this can be as fast as a week (not to mention atmospheric turmoils like sand tornados in hot areas); therefore regular campaigns of filter change is also a very sound practice
I was told that able to alert in case of filter clogging, based on clogging sensors or ventilation/temperature sensors, but never tested; if someone has experience on that I’d be glad to hear (or read..) about it