You'll have oil vapor being pushed out in a "chuff" on new engines. That isn't odd or indicative of anything.
Each chuff is a cylinder firing and pushing a little oil vapor out.
Most manufacturers have a scientific tool to measure the volume of blowby gases and will have a chart that shows the different ranges and what's acceptable.
The cheap way to do it is to get the engine up to temp. Unscrew the cap the whole way, flip it, and then set the flat part back down on the fill tube. If it dances around or pushes off the tube, the blowby is too high and you can expect to rebuild the engine sooner rather then later. If it sits there without pushing off, your blowby is fine. You might have to keep it guided in position due to the engine running and rattling it off, but it should dance around on top.