Take from an old house framer...
Simpson makes fantastic framing and structural aids; the piece shown in the video and its application are unsuitable for a weight bearing member. Pro bably fine for a light weight roof structure application, but as a former F HA inspector, I certainly wouldn't pass it as a floor joist.
First, the cut on the joist should be a cheek cut so that when installed th e face of the joist is in 100% contact with the adjacent beam. Think of a roof joist in a hand framed roof and what the rafters look like when nailed to the hip joist. A long, angled "cheek" is cut on the rafter, then it is nailed to the hip rafter through the cheek.
Second, when I build a deck (or an odd second story on a house) and it has that kind of detail (compound angle cheek cut) I do as Mr. Ross observed, a nd install a ledger board. Properly nailed to your weight bearing beam, th ey will hold a tremendous load. So, cut the joist with a cheek cut and sim ply set it on ledger. If the bearing point is open more than 1/8", bevel t he entire ledger the appropriate angle for bearing, then attach. Or you ca n notch the bottom or the rafter (my preference) with the correct angles fo r 100% bearing.
After the proper cheek cut, you can use the Simspon tie on a deck and it sh ould work fine with the proper framing web work as part of the structure.
I think it is important to note that the Simpson video only shows the insta llation of their product, NOT suitability of purpose or recommendations for proper framing techniques. Note that the metal hanger is shown on its att achment on one side ONLY. If you are framing a weight bearing floor/deck a nd it slopes, for proper framing the joists should buttress to a heavy, non flexing beam as the angle has transferred not only the dead load, but the live load (and flex) to the lower end of the angle on the structure. Also, with the heavier beam (to negate LATERAL flex)in place on the low side, yo u have effectively "trapped" the joist on place.
I would highly recommend using/borrowing/buying a copy of Rob Thallon's "Gr aphic Guide to Frame Construction". Having framed a couple of hundred hous es from top to bottom, and then 40 years of remodel, repair, rebuilds, and modifications to different structures, I thought I had seen it all. Nope. I still use that book from time to time for details. It is the best I have ever seen on all matters framing. More importantly, no methods or details I have used in that book have ever failed or even been unsatisfactory.
Robert