Most buyers let it lapse without a single call. A short checklist at month ten is worth more than the warranty itself.
A maintenance period is the window in which the builder returns to correct defects that emerge once a home is lived in. Timber moves, grout settles, doors drop.
The mistake is treating it as an emergency line. Keep a running list from the day you move in, then raise it in one batch at around the ten-month mark while there is still time to schedule the work.
Photograph anything you report. It is not adversarial — it simply makes the trade’s job easier when they arrive.