Yes, well aware of it, not quite as intimately as some modalities, but pretty thoroughly.

Have 4 or 5 books on it.

Its an integrated mashup of Gestalt Therapy and Transactional Analysis with a big hat tip to Beck's CBT for PD.

Interestingly, it has both Group and Individual modes, as separate methodologies (that can theoretically be combined,) as opposed to the split function of DBT invidual therapy and group skills.