Honestly believe what you want.

Unfortunately many professionals in the area are unaware of the amazing physiological basis of the ear's self-cleaning functions in detail. (audiologists are only taught how to measure your hearing, btw, not about general ear physiology/pathology)
I worked in ENT/otolaryngology for a while and some of the PhDs in our group were working on the way cells leave the ear canal with wax etc. They sort of flow outwards in concentric circles from the middle of the outer ear (the canal opening) to the outer edge (pinna), with the dead cells/debris getting expelled continuously outwards. This process is super sensitive to almost any physical disruption.
I just don't take risks with anything eye or ear related. And tbh I never got a comfortable pair of IEMs that I could tolerate for more than a few minutes anyways... never got to try any custom molded designs or anything, but to me the enjoyment in sound isn't as good as over-ear cans either.