As a self harmer, if my T had experienced it and was able to recover - I think that I would find it as hope. So long as he/she didn't try to force their way of ending to be mine, I imagine they'd have both professional and personal experience to be a good guide & fit for that situation. I do think that people in general who don't self harm, don't (and won't) understand it but that's the nature of the beast. Having a T that can relate to you on such an intimate level would be beneficial to many people.