When are you considered non-incapacitated? When you heal wounds/strain not to excess your wt/st, or when you heal them below them? The corebook seems to be contradictory in this issue and I cannot find any faq/errata addresing it.

Yes...

IIRC (AFB) RAW is the following:

You are not incapacitated when you take damage which places you AT your WT.

You are incapacitated when you take damage which places you ABOVE your WT.

You are not incapacitated when you are healed to a number UNDER your WT.

You are (still) incapacitated when you are healed to be AT your WT.

I believe it's a common house rule for you to be no longer incapacitated when you are heald to your WT, because we all agree it's weird for them to be different.

RAW, Jamwes is 100% correct. P. 216: "He must heal wounds until his wounds are below his wound threshold before he is no longer incapacitated."

However, we also play the house rule that you are no longer incapacitated when you are healed to be AT your WT.