During the use of TC6's Infusion Altar, certain blocks can be placed around, like Tallow Candles or mob heads to reduce the instability and deter unwanted consequences. I request a way to set what blocks can serve this purpose.

Primarily, I want to add Botania's Mana Pylons to the stabilizer, as those things are surprisingly useless for how cool they look.

Botania's Mana Pylons are already stabilizers as noted in the Thaumcraft Integration page in the Lexica. "...and any variety of Pylons."

There is no way for us to directly add Infusion stabilizers.
Infusion stabilizers need to implement a ThaumCraft interface, which is something we cannot do for another class.