The good thing with LH is 500 minimum miles on all the mileage earning fares (or 750 for full economy) on NZ. But rarely is it worthwhile due to the high fuel surcharge.

I did once look into whether qualifying by segments was worthwhile - there are some routings within NZ where you can do 8 segments a day comfortably (and a few more if push the boundaries). I think the fuel surcharges need to come down quite a bit to make that worthwhile too.

Any pure mileage runs for *A tend to be overseas, but can help by adding segment here and there where allowed by the rules (at incremental cost of fuel surcharge).

Eg see if DUD-CHC-WLG-AKL-SIN-... is same fare as DUD-CHC-SIN-...

You are better off I think, doing mileage runs when you visit BKK. If you have time do BKK-SIN-BKK etc for very little. Also need to watch out for non-mileage earning fares, but on programs that reward higher class of travel (eg Miles and More) may be better off doing it in business than economy.