I hope you will see my post about the need to pump the tank every year
(or so) to keep the overflow from ruining the drain field.

I would say inspect regularly, pump when needed. Adjust inspection
rate based on how fast the sediment and scum accumulate. I inspected
mine about every 5 years and just pumped at 19 years. Pump requirements
vary with the load on the system. You can inspect it yourself, get a book.