There’s no requirement that an airplane used for Instrument currency actually needs to be IFR approved. Or certified.
Prime example being a DA-20 which is not IFR certifiable as it lacks pitot heat amongst some other things.
Here’s my question, why wats your time flying straight and level?
Is it sufficiently equipped to fly approaches ?
Take off and put the hood on at 1000’ and fly to an airport 51 miles away and fly 4-5 approaches with missed approaches then land and have your buddy do the same on the way back.
More valuable use do your time.
Oh and I don’t agree with using the safety pilot rule for time building as that’s as never then intent of the rule.
But if you choose to do so then get maximum use out of it.