So very important to be able to hit confirm off of F2 DF3 with this variation: on hit, obviously, you can just confirm into the meterless BnB for 35%, and on block you can cancel the DF3 to be plus enough for a D1 check to beat out any option other than armor. Haven't done precise testing, but theoretically if Tanya is at least +2 from the cancel, you could even teleport again and be safe since it's a 7 frame start up.
She's got a lot of negative frames but a lot of those are negative for a reason: B2 is a 13 frame mid that checks at 3/4 screen so if you're spacing and using it properly it shouldn't matter, D2 is always punishable, F42 is a mix up string between that and F43, BF4 and DB4 are grounded mix ups, air DF/B4 are aerial mix ups, Pogo 3/4 are mix ups, and BF2 is a combo ender.
Also B32 can't be armored through and leads to the same damage as B31 so that doesn't really matter, F42 is safe so you have to be prepared for that option out of F4, and all of her other strings that can be armored through, realistically, aren't going to be used outside of combos.
Tanya in DN can threaten with a 13 frame poke 3/4 screen, impose mix ups 1/2 screen with pogo and can threaten pressure with DF3 or F2 within the same range. The only place on the screen where she can't threaten you with anything is when she's full screen. She has Takeda's range with better mix ups, button speed and mobility, and great meterless damage. It seems to be a solid, if not the best, variation, in my opinion.