I think this particular anectdote falls into the "aroused" category you mention.

I've experienced a lot of "soft" limits breached and at the initiation of the submissive... and it doesn't take inebriation or subspace to cause it.

In fact, it usually happens because they know I desire something... and they decide they want to give it to me despite their former reservations.

But you are also wise to ask the question. The exploration of your limits is one of the most difficult things you will do with your partner. You have to be able to trust in him/her, and you have to be able to trust in yourself as well.