Thanks everyone for your advice!! We have been trying to find a specialist accountant, and someone who knows international tax law, and have spoken to an agency that deals with non-resident landlords in the UK but so far we're not getting the answers we need, but we will keep looking!
We are still in the processing stage of our petition (submitted march 2023 VJ est Feb for NVC stage) so hoping we have it sorted before moving on to the next stage. Worst case scenario, we can hold off sending further paperwork to complete the visa until I know fully where we stand with the house. Thanks again!