A laser does not have to have all five safety features to receive an FDA accession number. If any of the features are missing, a justification must be made as to why. The FDA then decides whether to assign an accession number or not. I've seen laser systems approved without aperture shutters but that's really about it.
Both CNI and Viasho produce portables that meet all five safety requirements. I believe that S-KY also now meets those requirements. What is actually shipped may or may not be the same laser that the accession number belongs to. For example, if a portable is shipped with a different tail cap that defeats the interlock then it is considered a different laser and should not be shipped under the existing accession number. Of course, this may not prevent it being shipped as the FDA inspection by customs will not know the difference if the package is opened for inspection because they do not operate the laser system when inspected. This is how many systems arrive in the U.S. without all the safety features intact.
We distribute for many laser manufacturers but we never order anything less than the accessioned laser system. We do not need the liability that comes with that. The only time we alter a portable is for the military as they do not fall under FDA requirements and that's only if they request it.
U.S. distributors of lasers do not need an accession number as long as the laser system was imported under one. If the laser is altered after arriving then the distributor bears the sole responsibility, from a legal perspective, for the alteration and any damage or injury it may cause. Any lasers manufactured in the U.S. must register with the FDA for each and every model of laser. The FDA is pretty brutal when it comes to enforcement. If a U.S. manufacturer is caught selling non-registered lasers they will fine the violator for each and every laser sold, they will require the manufacturer to recover every laser sold and refund the money to the purchaser. If the violation is significant they can also bring criminal charges.