Crossing a boundary and violating one are not the same act. Crossing happens inside a frame that is genuinely trying to find its edges. Violation happens when care was absent, when the limit was known and disregarded, or when the Dominus's response to having crossed it reveals entitlement rather than error. The difference is not always visible in the moment. It is visible in what surrounds it.
A Dominus cannot prove he is worthy of that much trust before the work has been done. Anyone offering that proof in advance is offering theatre. What he can do is demonstrate worthiness across time, through consistency, accurate perception, and the discipline to govern himself as rigorously as he governs the slave. The demonstration is the only proof that counts.
The benefits this series described are real. So is the disappointment of those who chased them and were burnt. Both can be true, because these benefits are not properties of BDSM. They are products of a structure taken seriously, and without it the same acts that refine will instead corrode.