The strong n-terms abc conjecture

Let $n\ge3$. For non-zero integers $x_1,\ldots,x_n$, write $\operatorname{rad}(x_1x_2\cdots x_n)$ for the largest positive squarefree divisor of their product. The strong n-terms abc conjecture. There is a number $M_n$ depending only on $n$ such that, given non-zero integers $x_1,\ldots,x_n$ satisfying

$$\gcd(x_i,x_j)=1\quad\text{for all }i\ne j,$$

and

$$x_1+\cdots+x_n=0,$$

one has

$$\max_{1\le j\le n}|x_j|\le \operatorname{rad}(x_1x_2\cdots x_n)^{M_n}.$$

This is a modification of the n-terms abc conjecture discussed in Browkin's work, replacing the global gcd and nonvanishing proper-subsums conditions by pairwise coprimality and nonzero terms. Its status is not resolved in the supplied source.