1) Stat weights can be calculated from the values you posted me.
Avg heal/non hasted cast time - Avg heal/hasted cast time = Δheal/Δ cast time. Divide that by 26.5 and you get Δheal per 1SS.
Now compare that to the Δheal you get from +1 mind and you can calculate Δheal(1ss) / [Δheal(1mind)/100] to get the percentage.

There would be your normalized stat weight for +1ss.

Theoretically that would be incorrect if the game doesn't resolve SS below that .01s cast time threshold.
It would essentially mean that 25ss would be worthless until you pass the 26.5 mark and get that cast reduction.

Though I don't need concrete math to tell me that melding SS materia is virtually useless. Scaling is FAR too weak for the limited amount you can actually meld due to stat caps on items and limited slot numbers. You need 3 SS materia (26.5 SS) to get .01s of cast time reduction. Suffice it to say: you will not feel that effect in practical play. You most certainly not feel it in a way that would differentiate from a heal landing in time or not landing in time.

2) People DIDN'T try to help the OP. That is the point.
The responses he got were essentially: "you don't need to know that to play the game".

I agree that his switch to "me want to see % values" was kinda ... weird, but that doesn't change the issue: When he asked for mathematical data, he was greeted with hostility and arrogance "lul stats are so easy lawl why you need 3rd party opinion" responses.

YOU were the first one to actually link mathematical data in response to my post. So as far as I am concerned, your post was the first constructive & helpful post in regard to the OPs question. (Even if you didn't link stat weights directly)