Breakers trip due to load on the hot, not the neutral. Splitting a MWBC into identical but isolated circuits doesn't change anything. You need to reduce load on each circuit, so you'd have to add a third circuit (or more).

If you have access, start by pulling a new home run for a dedicated fridge outlet. That alone may resolve your issue.

Breakers trip due to load on the hot, not the neutral. Splitting a MWBC into identical but isolated circuits doesn't change anything. You need to reduce load on each circuit, so you'd have to add a third circuit (or more).

If you have access, start by pulling a new home run for a dedicated microwave or fridge outlet, depending on which is easier. That alone may resolve your issue.