If I had to homebrew a quick fix, I’d suggest something along the lines of “When making an attack, check, or saving throw while under the effects of a spell or feature that allows you to add additional dice to the d20 roll, such as Bardic Inspiration, you may only gain the benefit from one feature on a single roll. If multiple features would add dice, you may choose which feature to add the dice from when you roll.”

You don’t need to because bounded accuracy doesn’t need to exist, often it’s actively detrimental. See the common houserule that some checks can’t be attempted without proficiency.