Actually, the OTSRs are there to improve throughput, eliminating the need for the seat belt which has to be bucked BEFORE the lap bar on the other installations. OTSRs speed the load process, with riders simply pulling it in place and then latching the belt (like on many of the B&M coasters) so it's not wait for the seat belts to get checked, then lower the lap bars and check them.
Here's the thing about seatbelts, they're nowhere to be found on the original version. Case in point just look at the video of S:UF at SFDK.
https://www.youtube.com/watch?v=Ob0yjL2wOQY&feature=player_detailpage#t=129
Over there it's just a lapbar and nothing else, as plain and simple as it get's. Remember this kind of coaster uses Premier's newer trains, NOT the kind of trains that can be found on the Flight of Fear coasters which do involve seatbelts.
Also, it's being reported that BGW's coaster has more then just a OTSR, but it's also using the lapbar as well. So one has to pull the lapbar down, then the OTSR and then connect the OTSR seatbelt to the lapbar. This is not helping thoughtput whatsoever when they could've just had just the lapbar like the other versions of this coaster.
Now there is a thought going around that possibly they're using the OTSR to have a lower height requirement, now if that's the case then it's still something I really disagree with on doing since capacity and thoughtput is already going to be bad enough as it is...and you're going to make it even more complicated with the restraints just to have a even bigger crowd get in line for it?
3/19 UPDATE
Alright, a good amount of stuff has been revealed since this last post. The cars/train have arrived on site and it is now fully confirmed there are OTSR's. They look to be a fairly thin rubber, like as thin or thinner then Intamin's strap restraints without the padding. (No idea if there's going to be padding added to these restraints, but they don't look too pleasant. Not the kind you want to get pushed to the side or hang against...which is what will happen.) Also as reported earlier, both the lapbar and OTSR are compleately seperate from one another. So one will have to pull the lapbar down first,
then pull down the OTSR,
then connect the OSTR to the lapbar.
Also today there was a leak on the BG's website, showing the page for Tempesto. It was quickly pulled, but not before many people could screencap the page.
https://www.facebook.com/BGWFans/photos/pcb.10152819760973721/10152819759553721/?type=1&theater
Perhaps BGW pulled it because they realised on the page they have a name generator that is incredibly stupid. (Seriously, Six Flags Magic Mountain came up with a far better name generator to promote Twisted Collossus.) Though the page also reveals the height requirement for the coaster, 54 inches...which is
exactly the same as it's west coast and European counterpart. Which really does beg the question, if the height requirement is exactly the same as the same coaster that features lapbar only...why on earth were OTSR's added to this one?