Correction/Addendum to “The extremal function for the complex ball for generalized notions of degree and multivariate polynomial approximation” (Ann. Polon. Math. 123 (2019), 171–195)

We correct our calculation from the paper in the title of the Monge–Ampère measure for the $P_{\infty }$-extremal function of the complex Euclidean ball in $\mathbb C ^2$. In addition, we indicate how the Monge–Ampère measures for the corresponding $P_q$-extremal functions vary with $q$.