I went through the same thought process over fake strobes and certain other gear.
Settled the matter by deciding to buy safety equipment and critically important things straight from authorized dealers and paying full bore prices.
You likely qualify for discounts anyway.
Other stuff I do sometimes buy on the used market, and if I am suspicious of it and contact the manufacturer, they usually always tell me what to look for, and I tell them who sold it to me if the seller is a large volume guy. KAC is the only firm that would say only that mine was fake, and only because I sourced it from a private party who is someone other than KAC (my KAC sight came with a rifle attached to it).
Even a used genuine strobe is more likely, even after a pre-mission test shows it works, to operate intermittently or fail when in use, and you must dismount it to check. Too risky for my purposes.