From Chris Miller's paper in 1995, the structure $(\mathbb R_{an}, (x\mapsto x^r)_{r\in\mathbb R})$$(\mathbb R_{\mathrm{an}}, (x\mapsto x^r)_{r\in\mathbb R})$,is the largest known polynomially bounded o-minimal structure as of that time. I wonder if it has been confirmed that it is the largest one or new examples have been found.