I tested them on A with monk gloves and got mixed results. The essence that gives negative energy works, but the sonic and acid give you an error message that it needs to be applied to a melee weapon or creature weapon.

I assume the intent is for them to either work or not work on gloves rather than this inconsistent result.

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Tark Hammerfeast - Immovable Object
True Greenspan - Bendir's Boy Wonder

This is working as it should. Let me explain what is happening -

These all run off the flame weapon script, so when you use one essence it fires off and applies ot the monk gloves, but when you use a second essence it looks for the off hand weapon since that is how our flame weapon script works now. The thing is with monk gloves you don't have an off hand weapons so there is just an empty spot - thus the error message fires off. Now, if you rest after using the first essence and then apply the second essence you will find that it works. Basically once you use one essence you can not use a second until the first either wears off, or you rest and it is canceled.