OPC's could still be conducted by company TRE's, but LPC's should be examined by TRE's entirely separate from the company, and unknown to the candidates, otherwise low standards might be allowed to prevail.
of course realise that this would need a complete redesign of the logistics and economics of LPC SIMs, but I would have thought it would increase standards and safety.
I believe it to be a very good idea....for example Star alliance TRE should be going from one airline to the other...basic knowledge of company SOP and off you go.