There is one potential benefit to the gun buyer if the FFL does not transfer upon default proceed, which may be more desirable (if at all of course, would be a fringe personal preference) in normal times where checks are actually getting done at a reasonable pace..
Say you own 82 guns and maybe out of those a few are something unusual, ie NFA, or fall under some technicality, like maybe even just pistol braces. Then you decide you want this bolt action .22..
If that delay comes back as a denial, which can happen, and for whatever reason ATF (or local authorities if notified) decide this is the one they need to collect ASAP. Potentially now someone comes to collect your new .22 and scoffs up everything you've got, throws them in a pile in the trunk of a cruiser then into a wet basement
, possibly starts scrutinizing it all, measuring barrels and AOL etc etc
Sure in the realm of likelihood its low, and even then, 1st you would normally be called by the FFL to turn it in, or even by the ATF to do the same, but they do sometimes take it upon themselves to just go and collect.
Anyway, long story short just saying if something has gone wrong in NICS, there can be a benefit to not getting the gun.
In the case of the current FFL, usually they don't charge for the gun until the check clears. Any FFL who makes you pay for the gun first then doesn't offer a refund upon delay is an a**h***. Usually even if you didn't pay for the gun they ask if you want to cancel the whole transaction upon a delay, since some people just don't want to wait.