The buffs section can only handle macro-text that can be resolved on the sheet, before going to chat.  So anything that requires a dice roll, like [[ 1d6 ]] needs to happen in chat, post sheet-worker(javascript).    You can manually include a query for Inspiration within the macro-text of any given roll on the sheet.    You should be able to add something like  "  + [[ ?{Inspiration?|no (0),0|yes (1d6),[[ 1d6 ]] } ]][inspiration]  " to your attacks and skill check macros.  If you're not sure where to insert them, just ask.  We have added additional attack/damage macro-text on the beta version of the sheet which should make this easier with the next release. Cheers