Why three? When mine clicks off, on a slow fill, it's finished.
I once had a pump fail to click off on slow fill and I had gas all over. Long lasting paranoia so 3 clicks!!
Wary of the engine management issues and recommendation in manual, I initially started filling car to first click off on full flow. With the 280mm sender I consistently got a gauge reading of only 77% full though.
I then followed up subsequent fills with a few seconds wait then a slow to fast fill until second click off, adding several more litres. This leaves gauge showing 100% which doesn't drop for at least 10 miles of driving.