Micron rating doesn't determine flow. Media capability does.
Looks like a typical 20mm threaded, with bypass, oil filter. Wix 51334xp or Purolator PBL14461 or Fram FE9688.... used by numerous 3-6 cylinder engines from 1.4-3.6 liters. I doubt that your Yanmar would even stress the filter much.
Adequate oil supply comes from your oil pump. Your filter choice shouldn't make a difference.
What you read on Green tractor is not much different than worrying about the monsters in the closet and boogeyman under the bed. There is way too much misinformation and ol' wives tales on the internet.