Parabellum do you have any evidence for your assertion that this will not
affect the insurer's approach.
During a period of aviation recession I spent nearly three years working in the London market, dole wasn't an option. Regularly crashing and killing people will certainly get an airline a higher rate but that is a bit different to using lesser experienced junior crew. The aviation market is currently oversubscribed and competition for the business is stiff, insurers aren't going to start arbitrarily introducing limitations if it will affect their share of the business, as I said, if the airline is subject to recognised and proper regulation and the regulators allow the use of P2F, that will be accepted by underwriters until such time as they have justification to change or introduce additional premiums.
Both Lloyds and the companies market have their own, separate, survey departments who will have looked into and will continue to monitor the P2F situation, if it is the considered opinion that using P2F justifies an additional premium then it would be applied across the board and not individually by some lead underwriters but not others.