14 months for probing sounds good to me. 12 months is what I've read as recommended, but I know I'd want to wait a couple more months.
I'm personally not against handling the little buggers to get them to change perches, or something like that, especially when it's an experienced keeper doing it. I'm just against the idea of it being generally ok to do it, because more people have access to them these days, such as myself, and some of them may not be experienced enough to say, not flinch when it bites, or not squeeze too hard if it freaks out and tries to dive for the floor etc etc.
I think that the general information floating around this site about the matter needs to be to err on the side of caution, if you do it at all, outside of changing perches around etc.
At the end of the day, people are going to do what they think is correct with their snake, but the last thing we need is newbies coming on here, buying a GTP, and not finding material that warns them of their fragility.