Try not to flex the wrist, regardless of alternate picking type (inside or outside picking). Instead try wrist extension.
As you probably know most of us pickers have an issue with alternate picking, inside picking in particular or at least I have struggled with it for long. In detail while continuously inside picking a pair of remote or even adjacent strings we are able either to pick cleanly but slowly or fast but sloppy (unintended „hit“ the wrong string(s)). That happens because of „string hopping“. String hopping in turn occurs because of wrist flexion while rotating the forearm. Wrist flexion works only for outside picking!
Now, what if wrist flexion is desgarded completely and the wrist is kept extended at a constant angle while rotating the wrist? E.g.
A very small angle a for the strings e and B,
A bit larger angle b for the strings e and G,
… e and E.
You get the idea.
Works for me. I‘m curious to know if it does work for you too.