pidzi,
1) If your vanilla TE is in another folder and you didn't specify another Mods folder within its Mods.ini, it cannot interfere with your ITST Modding on another drive or folder. So it might be a bug...

Or maybe you have tweaked your Tennis.ini ? (although it shouldn't influence the .dmo replaying, as normally all meaningful game parameters are saved in the .dmo )
2) I had checked the Precision formula too quickly and didn't notice there was a 2nd line in it.

So it's actually : Elite +19% = Simu +0%.
Also I wasn't clear in my previous message, but I meant in Free Mode (ie: when the skills aren't remapped, like in the ITST Mod and normal offline mode).
If you did your tests with the Fair Mode still on, then you actually got +5.4% ( = +9% * 0.6 ).
So a true +9% is noticeable, but less of a game-changer than switching from Simu to Elite.
I took a few screenshots in a standardized test to clearly view the differences, using the normal strike with a preparation time of 0.1 seconds (ie: if you play online with a Delay above 100ms, this strike will be seen as a no-button strike), 100% Consistency, and the ball not exactly in the center of the cords so the Sweetspot is 0.2 in Simu which gives 0.25 in Elite :
TE2013_Simu+0.jpg
TE2013_Simu+9.jpg
TE2013_Elite+0.jpg
TE2013_Elite+9.jpg
TE2013_Elite+17.jpg
I think it clearly shows the Simu+9 has a significantly lower chance for the ball to go out, and it can't be as short as the other setups.
Oddities :
- perfectly centering the ball will make it deeper and thus gives more chance to make it out
- a lower Consistency makes the ball shorter and thus removes the possibility to send it out ; this means once you're under 80% Consistency, the strike has 0 chance to end out with Simu+9 while still a decent chance to be out with Elite+0 (ie: it's a game-changer in term of defense, but has little effect on the attack)
3) They are too many things going on in determining the Rally Length so it's hard to conclude something only with it, especially in CPU vs CPU matches
4) I'm not sure where you are in terms of Consistency for your ITST Characters, but as outlined above, lowering it may benefit defense more than the attack, especially if the user isn't comfortable with stepping on or in the baseline.
Also, you get a +1km/h Speed bonus for the Short Acceleration per 20% of Consistency.
Your CPU vs CPU test is indeed surprising ; one thing that comes to mind is that the CPU doesn't position himself perfectly up/down (ie: sometimes I make him step inside the Danger Zone to simulate a little mistake) and thus could be making more mistakes with a lower Consistency. You can check the error stats to confirm or infirm that.
Else, it's quite possible that the shorter balls gave more attack occasions or allowing to rush the net more. Again, the winner stats & net rush might help to determine this. Also here as well you should evaluate if the common ITST user can exploit correctly the shorter balls without the help of the Danger Zone (or at least the Impact preview).
5) I quickly checked my reflexes in-game and I can get as low as 100ms (without cheating

) but also as bad as 267ms...

So I guess the main advantage you have over me is the stability of your reflexes, even if the online test shows only a ~25ms difference.
I'd still be interested to get an idea of the reflex levels of your fellow top ITST players, even if the correlation between the game & the online test isn't that great.
Or maybe they can test in-game : need to go in warm-up, send back the 1st ball to the opponent, not move, wait for the opponent to strike left or right, start to run left or right correctly, and then check the replay in the step by step mode to count how many frames it took you to react after the 1st frame where the ball changed of direction and then you can multiply it by 16.7ms. Note : in Step by Step mode (ie: replay is paused), B1 = advance 1 frame ; B2 = rewind 1 frame.
6) If the v1.2 felt perfect (or near of it) before the last TE update, it might be possible to tweak a bit the Character Skills to reach the same state.
So 1st :
ANd now its even more pronounced as last TE update rendered short accels less effective in power and precision when precision is +0 and less
You may have misunderstood what the update did.
1st, the strike precision didn't change except when the Precision skill was above the Power by 20% or more (I guess it's not the case in ITST).
After, the maximum speed bonus from Precision vs Power of the Short Acceleration was for +20% : 7.5km/h ; now it's 4km/h.
So if you have a Character with +10%, he had +3.5km/h which is now +2km/h.
There's also a Precision speed bonus which is +1.5km/h per 10% of Precision (ie: 0 at 0% and 15km/h at 100%)
So you can raise the Precision by (3.5 - 2.0) / 1.5 * 10 = 10% to get the same speed.
Also, the speed from Power is +3km/h per 10% Power (but only for low spin balls), so you can raise the Power by (3.5 - 2.0) / 3 * 10 = 5% to get the same speed. (with a heavy spinner, you'd have to raise it a bit more)
Considering this, I guess I'd try a 3% raise on both Power & Precision ; this would give a bit more speed on the normal acceleration and an acceptable tiny loss on the Short Acceleration.
However, maybe your main issue is the loss of the speed bonus on off-centered balls. For this, there's no easy fix.
7) The short acceleration is best with a high topspin because in such a case it's less slowed down when the ball is hit low. Your last try was with 0% topspin so it might be normal that the short acceleration wasn't that effective, even on clay. A 35% Topspin skill may give a different result.
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