I had a 1992 968 for 5 years or so, and researched the 944 and 951 platforms fairly extensively when I was shopping around as well. There are more similarities than differences.
Back when I owned the 968, I thought M1 was the best there is, and I was repeatedly told by mechanics that I "needed" 15W50. This was heavy stuff (API SJ days, I think? Red cap.) From my knowledge at the time, it was considered "normal" for the oil pressure warning light to flicker and pressure read 0.5bar or even lower at idle if you were running on the "thin" side and it was hot. I assume this would be 30s and thin 40s. This was in the owner's manual, and talked about in forums at the time. With my 15W50 I would idle at 2bar once fully warmed up (5bar when cold). Pressure would rise rapidly from 2bar as well to 4-5bar at most operating RPM ranges.
Your 2bar at idle is no problem at all. Porsche says down to 0.5bar is fine (but I certainly wouldn't be happy about it). I don't have it on hand, but Porsche specs how quickly it should rise (x bar per 1000 rpm) and that it should reach a minimum of y bar by z RPM. Those are the parameters you must be mindful of. Main bearing load while idling is virtually nil.
Now, before I sold the car I did one change with M1 0W40 since it was the new recommended weight for all Porsche I thought I'd give it a try. Idle was still around 1.5bar.
Now, I always thought the 15W50 was a bit thick. During warm up the engine was obviously fighting the oil and in the cool weather of spring and fall it was REALLY thick. So thick the gauge would slowly fall from 5bar to 0 over 5 seconds after shutting the engine off when still cold. Crazy.
The M1 0W40 really changed the character of the car. Start up and warm up was much more civilized and some pep was released at all temperatures.
If I knew then what I know now, I probably would run 15W40 HDEO and see what the startup/cold character was like. If high heat or track time was expected, probably 5W40 HDEO. If I bought a 968/944/951 again, I would not go the 15W50 route, and I would not go the M1 0W40 route. M1 0W40 shears pretty easy, and my 968 driving habits sheared even the M1 15W50, which does not shear easily.