your channel states you go where few or no foreigners have been before in Thailand...I checked a few of your videos but didn't see anything remotely like you being the first westerner to discover the place. Where exactly have you been that no other foreigners have been before in Thailand?
there may be some coverage on previous injuries etc looks like it depends on timing of everything. From Pacific Cross;
"A pre-existing condition means any medical condition (including conditions that are a consequence of the said condition), which presents signs or symptoms in a period of 5 years prior to the first policy effective date that would cause a reasonable person to seek diagnosis, care or treatment, or for which diagnosis, care or treatment was given before the policy effective date."