First of all, we can see that characters have different views of what the Absolute actually is. Some believe "the Absolute" to be female, some characters believe "the Absolute" is male, whilst the mind flayer that captured us relates that: "You see other mind flayers arranged in a serene circle. Absolute unity. Absolute power", upon casting speak with dead on it. Perhaps it is because the thought of the Absolute being a female to a drow priestess from Menzoberranzan is more convincing or pleasing, as is a war-like male deity to certain goblins.
That could be the case. It is also imaginable that the developers changed plan. I think some goblins refer to the absolute as she. There is an unused? dialogue entry about a vision that reveals
that only a priest of the dead three can remove the tadpole
The involement of the dead three is a given. Their symbols are the symbols of the absolute. It is curious that characters well learned in the lore do not point that out. Surely a cleric of Shar would also recognize the symbols of Bane and Myrkul?
Someone in the datamine thread found out that
using the tadpole a lot can give true-souls power over the character. I guess that this confirms that they are controlled from afar by the Absolute.
Regarding the Minthara True-Soul speculation: There is an intimidation check for Minthara. "You wouldn't dare kill me - I'm a True Soul, same as you. She answers "That might be. But you have not been truly tested yet" That is not a full confirmation. Why would the absolute not use the control over all its clerics?
I sometimes use thought experiments. I don't necessarily believe in every idea I post for discussion on this forum