Yes, the equations in your 3/18/2022 post seem to be correct to get the percentage of interest before June 2021 and after June 2021.
I do have a question for you to clarify. This refinance was on a rental property you owned and you took out cash to purchase a second rental property, correct?
Just to be clear, you can deduct interest on a loan used to improve rental property as a rental expense, even if the loan is not specifically secured by the rental property.
