However, if the product is defective you have 2 years to return it regardless of where you bought it.
I'm not 100% sure how the purchase process works, but from what I've heard they tell you to scan your head using the iPhone's depth camera thingy to get the headset properly fitted for you. I think they're just selecting presets for generic parts, but if they do any kind of customisation for you as part of the process, you may not be able to force them to accept your return.
Also returns don't apply to hygiene senzitive products that are worn on the body, products tailor made or made to order, so those Zeiss lenses tailored to your diopters or the facial interface sized to your face plus the hygiene angle where the strap and facial interface on the used items will be full of sweat and oils, might legally disqualify you from a refund.
I'm sure Apple has taken steps to account for large numbers of returns and have a program to refurbish and resell them back on the market, but based on these limitations they're not mandated to accept them by law.