Dude,
Check out the promo,
https://www.youtube.com/watch?v=AeZVgY1dvkU
To me it suggests hologram or use of speed powers, or a combination of both rather than time travel.
(by hologram I mean projected light, so an illusion, not a solid hologram like in Star Trek TNG, just to be clear).
At 0:08 Cisco is looking at the RF standing in the forcefield, to me, this screams hologram, at 0:15 he's looking at the 2 Wells figures vibrating side by side......again, hologram ?
Or if a combination of both... if we link the quick scenes sequentially, Cisco looks at the RF in the forcefield, then we see Caitlin looking at the empty wheelchair/glasses at 0:11. So Wells has used super speed to run to Star Labs, where Cisco has discovered the RF recording, then is showing Cisco how he could appear to be in two places at once.
It's a possibility, and to me gets around the complications from having two versions of the same person exist in the same moment of time.
Again, I'm not saying you're wrong, just that to me the hologram/super-speed solution looks a bit simpler.
Anyway, we'll know soon enough, roll on March 17th.
The big question is that once Cisco knows, what will Wells do ?