TBH, I'm not sold on this route. Even with the zips, I'm unsure if it's overall faster than the current RTA route.
Underground Reservoir (activate warp room)
Study (enter using the back door near Great Armor)
Chapel Warp (to Entrance)
Top Floor Warp (to Underground Reservoir)
Arena Warp (to Top Floor)
I'll try and break down my reasoning why this may be the faster route.
Start to Chapel Warp:
RTA uses the Underground Reservoir to access both a warp room and the rear entrance to the Study, reducing the travel time to Great Armor. Once Manticore is down, the warp room is right there ready to be used.
The Underground Reservoir route is slightly longer than using the Main Corridor, but spits us out at a better position, as there's no detour to get to Great Armor. It also gives us a convenient warp point for Legion later. Manticore is fought at the same strength he is in this TAS, though Great Armor would take slightly longer due to lower stats.
This TAS deals with Creaking Skull first, then heads to the Inner Quarters warp room, which a decent detour from the Main Corridor. It then zips to Manticore, then makes the trek down to deal with Great Armor.
While the zip definitely saves time, that time is then lost by having to make 2 trips through the Study. I'd say this TAS would come out slightly ahead if it didn't detour for the Inner Quarters warp, but with that I'm estimating both routes are pretty much dead even as of the warp in the Chapel.
Entrance Warp to Top Floor (RTA) and Arena (TAS) Warps:
This is where the routes really diverge, with RTA dealing with Creaking Skull, Big Golem, and Headhunter, ending with utilizing the Top Floor Warp, while the TAS route heads to the Floating Garden to zip to the Arena, and deals with Balore and Legion, ending with using the Arena Warp.
My estimates have the RTA route entering the Dance Hall at about the same point the TAS route is initiating the zip, with both routes entering their respective boss rooms at the same time. Big Golem goes down first, and RTA should be entering the Inner Quarters at about the same time Balore goes down.
TAS route should be entering Underground Reservoir about halfway through RTA's fight with Headhunter, and starting Legion as RTA enters Top Floor. Realistically, RTA should be warping from Top Floor as TAS finishes off Legion. TAS then still has to get back to Arena warp, putting RTA ahead.
Underground Reservoir (RTA) and Inner Quarters (TAS) warps to Death:
The trek from the Underground Reservoir warp to Legion is slightly longer than from Arena, so this would put TAS warping out of Arena slightly before RTA starts Legion. Legion would drop faster than it did for TAS due to +1 (or 2, from Manticore) Orbs. This should put TAS starting Headhunter at about the same time RTA is exiting Legion's room. Headhunter for TAS would go slightly faster than for RTA due to +1 Orbs. In the time it takes for Headhunter to go down, RTA should be just outside of the Arena warp.
TAS should then be somewhere in the Minotaur hallway when RTA starts Balore. The higher Orb count (6 for RTA, 3 for TAS) would make Balore a fair bit faster than for TAS, reducing the cycles for phase 1 by 1. Phase 2 has reduced defense, increasing our damage output, which makes it preferable to push him into ASAP. RTA should finish Balore off a bit before TAS kills Big Golem. The time it takes both to reach their respective warp rooms is about even (would be tipped in RTA's favor if not for the elevator...), putting RTA slightly ahead at the warps.
The big difference here is that RTA is warping to Top Floor while TAS is warping to Inner Quarters, giving RTA a sizable lead.
Everything from here to the end is identical.
Now don't get me wrong, this TAS looks really good, the route itself does look as if there was a lot of thought put into it. And really the route is my only gaffe with it, everything else looks fine (except the Crucifix use on Balore, I'm pretty sure jump kicks would have been a bit faster). Makes for a difficult vote.
I think I'm gonna have to go with Meh, and hope the route I posted above is looked into a bit more for TASing.