Given you could even use it commercially (it requires an enterprise license, but I suppose Matlab does too), moderately useful conceptually, weakly useful mechanically. APL is very limited in what offers you. I did a ML course in Matlab a while ago and I remember I could scalar loops and procedural scripts, had nice tables and object-ike structures. You'd give that all up in APL so it wouldn't help you there, but you'd see how far you can get only with creative 'array language semantics'.