My suggestion would be to do all the research first, then rent a few of the lenses that come out on top of your wish-list. You only have a right to return any product because it's defective, unmerchantable, or not fit for the ordinary purpose for which it is intended, in the U.S., all other returns are dependant on the grace and good will of the seller. (Unless, of course, they've made some positive statement amounting to a promise of convenient returns for good reason, bad reason, or no reason at all.)
That said, I know a lot of folks of the feminine persuasion routinely buy clothing (and especially shoes) online with the clear intention of returning them - Zappos' made its business doing precisely that prior to assumption into the Amazon dimension. Something like highly technical expensive equipment like lenses is a whole 'nother story, though; when the seller gets it back, they can no longer sell it as "new", which means they lost more than the profit they'd have gained from selling to you, they have to sell it to someone else at a reduced price. (Reselling a returned item as though new is unlawful, though some do it.)
My personal feeling is that buying things with the intention of returning them other than because of a defect is fraud. The intent in such cases is not to make a purchase, but to try out the product at someone else's expense; but the purchase and sale of the product amounts to a representation of fact that it is intended to be a serious purchase, not a "try it and see", and that amounts to a false representation. Or in my terms, a lie amounting to theft. And, as I said, that's all off when the seller has warranted the purchaser the right to return stuff no questions asked for no good reason. It's clearly ok to take them up on that offer, it's only when the act is deceptive that it bothers me.
Last edited by dlhawes; 12-10-2021 at 05:59 AM.