Yeah exactly, as I say, vague
All VW are essentially saying is, so long as the switch remains closed at 1.2 bar, all is good. No mention of rpm below 2000rpm.
Therefore one can assume the engine is happy if doesn't throw the oil light on the dash, because they are assuming if the pressure is good at 2000rpm, it's good everywhere else. Very strange.
Old VWs used to have oil pressure gauges, but since the 2000s, they stopped fitting them as to not alarm people about the low pressures at idle when hot!
From the data you've gathered so far, it would seem yours is where it needs to be.
Mobil do a 5W50 for older engines, which I would favour over a 10W60, which I know some folk have run in the past. That would certainly help prop up the low rpm pressure a bit. It's a band aid I know, but not sure what else you can do short of fitting a brand new pump @ £1500+VAT!