X-Plane never uses OSM data directly. OSM must be converted into some kind of X-Plane scenery.

Some users are making third party scenery with Jonathan Harris' tool. I do not know if he uses one-way or layer. LR has not already shipped global scenery using OSM.

do you plan to use all available data in xplane long term…or is that simply too much data?

The data will almost certainly be filtered – OSM contains tons of weird stuff, whatever someone wants to tag, so it is impossible to say "I will use it all" – there can be data that we simply don't know how to interpret. For global scenery we may also have to omit some roads or ways due to file size (e.g. not include all foot or bike paths).

It will be possible to create custom scenery from OSM that is potentially even more detailed than the default scenery, for those whose machines can handle it.