Most voting systems with a status quo bias (such as decisions about constitutions) have that bias in form of a requirement to get much more than 50% for a change proposal to pass, for example 75%. Status Quo Approval has a bias, while it is still possible for a change to happen that has simply more than 50%.
The ballot is like an approval ballot, which means the voter can make one mark per candidate, but mark as many candidates as approved as the voter wants.
Only if the status quo gets less than 50% approval a change is considered. That's status quo bias and there is more of that. We then look if the candidate with most approval has more than 50% and only if that requirement is also met the SQ gets changed and the one with most approval is the winner.