I'm glad when an organist has more possibilities from his instrument! I am happy that my suggestions are useful!

Good morning!
I explain what happened.
The Tracker Touch function is subordinate to the Midi setting parameters of the keyboards only when it is set to "On".
When it is "Off", a mathematical average of the "Attack" values ​​of the stops is calculated, and remains unchanged (in reality, up to a certain point, because the system always processes information on the air flow of the pipe, which vary if a note is repeated).

When the Tracker Touch is set "On", the system obtains the velocity data by the keyboard (or on the fixed value of the key velocity set) and compares them with the data of the "Attack" parameter set on each stop.

The highest key velocity corresponds to the maximum value set manually on the "Attack" stop parameter, while the minimum key velocity value always corresponds to the maximum absolute value of "Attack".

I give an example:

Rohrflote: Attack = 2 (a low value corresponds to a fast attack)

When the key velocity is at maximum (127) it corresponds to the Attack value = 2 of the Rohrflote. When the key velocity has lower values, the Attack parameter value (virtually) increase, and therefore the lowest key velocity necessarily corresponds to the "8" value of attack (slowest attack).

Now, let's take the example of the Rohrflote set with Attack = 8 (maximum value that corresponds to a slow attack).

Also in this case, when the key velocity is at its maximum, it corresponds to the maximum manually set value of Attack (8) and therefore, paradoxically, a very slow attack. When the key velocity is lowered, the Attack parameter always remains 8, because the system cannot go further with the values. However, even if the attack speed remains unchanged (very slow in this case), changes related to the sound of the initial air jet take place; therefore lowering the key velocity, even with an Attack parameter of 8, there will always be small variations in the noise of the initial air jet (chiff), which is very useful for imitating what happens in a pneumatic or electric organ.
This is because the attack speed of the sound is the most easily noticed element, but in reality other elements such as the type of chiff sound that is modified with the key velocity values ​​also intervene.

@Michael, Thanks!
Yes, in Italy, until the 1960s, when all organs were whit electric action, the largest companies (Tamburini, Mascioni) built concave radial pedalboards with measurements indicated by Fernando Germani; they were pedalboards who had to adapt to the eclectic style. According to Germani they could be used both to perform Bach, as well as romantics or contemporaries. The only company that kept the measures designed independently was Balbiani Vegezzi Bossi, wich they differed both from the AGO standard and from Germani's measures
When the movement of the historic organ rediscovery occurred at the end of the 1960s, the first mechanical organs were built, which however still maintained the eclectic ideal, and often still had concave radial pedals (in some cases only the keyboards were mechanical, the pedal was electric!). Only towards the end of the 70s were mechanical organs (in some cases historical copies) built with a truly historic sound aesthetic, and these instruments finally had key and pedal measurements with original measures.