The argument that you should use proportional star voting is a complex nuanced topic, and it is not at all established that proportionality is inherently Superior for producing outcomes, which best reflect the will of the people.
that said, if you’re going to do proportional representation, I would recommend just doing this.
https://www.rangevoting.org/RRV
you could certainly apply the top two automatic runoff to every round, but given proportionality already mitigates strategy, it’s questionable whether that’s really worth it.
also there 's are some variations on how to do the proportionality formula for star voting. I can say more if people are interested about why I think The method described in that link is the best balance of accuracy and simplicity.