Kioti DK 35 Crankcase vent question

[Coyote machine]

There is no issue with adding oil through the valve cover access, so long as you're not tipping a gallon jug into the cover; the issue then is the drain back holes in the head can not keep pace with the rapid oil flow from such as a gallon oil jug and will allow engine oil to "back up" into that vapor recovery tube mentioned. That may cause engine run-away as the excess oil admitted to the recovery system enters the intake manifold and, when the engine is started, the combustion chambers.

No issue until there is an issue, which stems from exactly what you describe above. Engine runaway as a worse case scenario is a serious issue in itself.
To the OP: Just because the dealer did not inform you to use the cap by the injection pump to deposit oil into your engine does not mean they steered you in the right direction. Daedong makes these engines for multiple markets around the world, and as such some things overlap, like in countries where emissions are less restricted then the US using the valve cover is probably not problematic due to variations in design, etc., etc.
Consequently, the added language barriers of English from Korean and adequate or 'complete' documentation may be at one's own peril. Not all dealers are able to fill in every missing piece of the puzzle- that's why 'DOG' created TBN. And here you are where all answers intersect....

 

[Avondale]

Thanks, this is good info I can use.