Yes, I’ve watched that video before (and it’s an ad for Phonak custom molds, to boot!). From my point of view, he overemphasizes the occlusion effect (“sound of your own voice you never get used to”) - I would disagree with that - and Dr. Cliff puts a big premium (#2) on hearing “natural” sound incoming from the environment - where I don’t find the low frequencies terribly affected - as I’ve mentioned before, I’d rather trap low frequencies from my HA’s in my ear (#4) rather than worry about whether external bass is having a problem getting in. My Quattro’s do an excellent job of giving me a very natural sound sensation even with a highly or completely occluding fit (YMMV). His video completely ignores possible issues of speech clarity from possible cancellation of HA-produced sound interacting with bypassing external sound, directionality control, and noise control. Thus, I completely agree with your conclusion:
It’s a multi-dimensional problem/decision and I don’t think a priori there is any way for a user to personally evaluate the importance of each factor to himself/herself and arrive at the optimum amount of venting that he/she prefers as opposed to just going with a population-derived value that’s supposed to work for you. As soon as I discovered that I could hear soft high-frequency speech more clearly going with more occlusion, the open vents prescribed for me were out the window. Same for ReSound’s proprietary comfort Audiogram+ fit profile vs. NAL-NL2, which gives more amplification to soft input sounds in the midfrequency range. If I decide to change volume, implement noise control, or change the relative balance of bass, midtones, and/or treble, since the sound I’m hearing is coming largely from my HA’s, the program changes are a lot more effective than if much of the sound I’m hearing is “natural,” bypassing my HA’s entirely and giving me no control over what I hear. Again, it’s an individual preference that may apply to some like me and maybe not a lot of other folks.
P.S. And if you have select-a-vent, you can vary the vent size for special occasions. You don’t have to be stuck with the “optimum” size (for what?). Going to a concert and want to hear as much natural deep, deep bass, go with more open inserts. Motorcycle racing like GreatDane (or just using a horribly noisy mower), close it up and don over-the-ear protection besides.