The Switchblade has full ASTM-1952 DH certification with and without the chinbar, for what it's worth and was one of the reasons I went for it (as well as Giro shells fit my head really well). The double D chinstrap is a huge plus for me too as my muscle memory kicks is built around those and I think they are a better, more secure strap method. The chinbar is very very easy to put on and take off, the adjustments work and a second visor with a go-pro mount is a plus as I mount my light to it using a small 3D printed part. The draw was that I could and do use it for everything on the Shore, Whistler Bike Park, you name it.
Now when I'm climbing I usually take the whole thing off and hang it on my bars like I would a full face....which starts to makes the removeable chinbar feel a trifle pointless unless I'm going up some kind of technical climb that I really need head protection. And then I always take the chinbar because I have it and it's trivial to hold it on my pack and I may change my mind about a route.
I might as well just get a full face and put it on for the descents as long as it fit as well as the Giro and was very well ventilated with the ASTM cert. But that'll have to happen after I amortize the cost of the switchblade which is still a very good helmet.