Question about Bolster Boon

For the Bolster boon, do you choose the single attribute to give advantage with when you purchase the feat? If so is it one of the listed attributes (alteration, creation, prescience or presence) or can it be any attribute at all?

Or do you get to choose the attribute to bolster whenever you invoke the boon? If the latter, can you choose any attribute to bolster, or any of those four?

Bolster isn’t a feat, so there is no choosing at the time of purchase.

When you cast the boon you choose, and you can choose any attribute.

The listed attributes are what you are able to invoke the boon with.

The effect states:

Choose a single attribute. The target gains advantage on their action rolls with that attribute according to the power level of the boon.

Doesn’t say choose a single attribute from the above, or from this or that, just a single attribute, so you are good for doing any.

Thank you for the reply, much appreciated! I meant the Boon Access feat, sorry about the muddled terminology.

I guess the attribute requirement basically determines how you are bolstering someone.

Boon Access you don’t have to worry about having the required attribute to do the thing, so you can completely ignore those.

for bolster, you’ll either want to invest 3, 6, or 8 feat points into Boon Access to make it worthwhile. You will still have to roll, but based on how much you spent on Boon access is your equilvant attribute dice. So if you spend 6, you would roll as if you had an Attribute score of 6 (2d8 as I recall).