That seems dangerous filling the gun up so fast. Just think of how many people would put more then the 250 in bottles with this. You would have to rely on your tank being at less then 250 bar so you don't fill it past that. If it would do a slow it wouldn't be as bad.
My concern would be the rapid expansion of the metal in the tank as it gets really hot. Yes, it is rated at minimum 2 x times the max pressure, but the rapid heating up and cooling off cycles are not good for any material.
I believe that all of your criticisms are unfounded. The only possible negative would be the heat issue from filling too fast but by observing the video, it appears to have a built-in restrictor that negates that problem. The other issues that you raise seem to me to be conjecture. I'm sure that a smart guy like Ed knows how to design and make a simple foolproof fill adaptor for the well-healed.
Yeah it looks to me like it fills a foster type gun too fast. And doesn't appear to have any type of restrictor with that setup. You aren't crazy Chuck haha.
I don't see why the device valve can't be modulated to control the speed. There is also the option to choke the flow with the tank valve, like any other filling system. why don't you email Ed or Edgun West with your concerns? I'm sure that they could explain away your criticisms.
I get what @CHUCK is stating. Without disassembling one, looks like it's a setup similar to a compressed air blow gun mechanism. This airgun version doesn't have the trigger travel to allow partial opening, and even so, modulating the air from a blow gun is next to impossible as well. Simple valve system that wants to either be opened or closed, resulting in a slam fill if there's no post-wand restriction.
Eaglebeak, you say, "There is also the option to choke the flow with the tank valve, like any other filling system"... well if you're going to do it that way then why would you buy this trigger device in the first place?
I think that the main objective of the device is to leave the system pressurized without wasting the air in the hose every time it's bled. The only waste is from the trigger to the gun. If you choke the bottle to a speed that you are happy with you can leave it set in that position and not have to worry about modulating the trigger. Closing the valve and bleeding the hose at the end of the session would be a good idea for safety's sake. I don't think it is fair to criticize a new product without a proper understanding of how it works and speculating on the type of damage that it may or may not cause. I use a regulated fill hose to fill my guns and I don't worry too much about how fast it takes whilst just topping off. I am however a bit more careful when filling from empty. IMO a half-full bottle would act like a pretty good heat sink and prevent damage to O-rings which would be the only parts that could be affected by excessively hot charging gas. I would be happy to have one of these in my parts bin but I assume it's way out of my price range and I already own several fill adapters that work fine without the extra luxuries.