Categoricity for transfinite extensions of modules

For each deconstructible class of modules $\mathcal D$, we prove that the categoricity of $\mathcal D$ in a big cardinal is equivalent to its categoricity in a tail of cardinals. We also prove Shelah's Categoricity Conjecture for $(\mathcal D, \prec)$, where $(\mathcal D, \prec)$ is any abstract elementary class of roots of Ext.