My experience with systems that are used periodically i.e. at set intervals but not continuously, is that when they are used it is "all hands to the pump" and they absolutely have to be up and running when they are needed.

There is a danger that an important repair is forgotten and you are left desperately trying to bring yourself back up to speed when it becomes an urgent issue.

The time to be pulling your hair out with these things is not when their failure is highly visible and everyone is looking at you.

I think the danger of having a "it doesn't matter if this doesn't work for a while" application is that it encourages sloppy practices and poor discipline.

It is very easy to fall into bad habits and to be lulled into complacency. It is only when you are badly bitten in the bum that you realise jsut how badly you lulled.