You will need to be current and competent on the SEP (and MEP when you get there) and also be up to speed with current legislation surrounding General aviation.
If you want to do the IRI in the future it would obviously require a single pilot IR so getting that back would be worth looking into although you have to decide when it's worth doing it. You can teach for the EIR (when it get approved at ATO level) as an FI which would be worth doing.