Foxmoth,
Surely it would be good to find those limits without the crash! This is why I said practice by working up and using an instructor till you find your personal limit. I doubt the insurance company could object to this or try to refuse a claim. If the pilot had records of training flights with an instructor who had seen him operate safely up to a particular crasswind figure he could argue that this was within his capability!
The main point I am making is that you must read what's written in the POH and take it at face value. If one pilot chooses to limit himself to 10Kt x-wind then I am sure that he would be quite safe; another pilot choosing 35Kt as his limit may or may not not be safe but, he would be legal (as far as comliance with this section of the POH is concerned)!
3 Point