I totally get why different approaches would suit different people and situations. I guess I don't feel mixing and matching within one treatment, unless long term, or clarified, is the best way, but flexibility and modifications definitely.

The therapeutic relationship goes beyond the trust and safety of course and that has been the OP's issue since there is something deeper going on that is there but not being discussed or handled in a way that feels okay to that person and so the question is about the approach in general as well as the particular people.

While I get that CBT is very technique oriented, the thing is technique has been shown to be less important than the relationship. So yes, to some extent all techniques have validity, but the technique is the least important aspect of the therapy even if it seems like it is the most obvious and important. In fact I think the technique account for as much effect as just a placebo effect. The client factors and relationship account for like 70% of why therapy works.