batching.js code comment. And add support for batching animated Skinned models?

I've got a code comment regarding:

                // Split by instance number
                if (i === meshInstancesLeftA.length) {
                    meshInstancesLeftB = [];
                } else {
                    meshInstancesLeftB = meshInstancesLeftA.slice(i + 1);
                }

Isn't the if (i === meshInstancesLeftA.length) { an impossible/redundant case check? You've already accessed meshInstancesLeftA[i] which is assumed within range and won't be undefined. i=== meshInstancesLeftA.length will never happen, i think. The else case should be sufficient enough, right?

Also, refer to the changes I did in batching.js on my fork that supports Skinned batching.
https://github.com/Glidias/engine/blob/master/src/scene/batching.js

Test project with scripts/3rd/modpc.js hacks wit batching (View in EDITOR).
https://playcanvas.com/editor/scene/613629
I tested with a bunch of soldiers + ships all using the same batch group, they seem to be all batched to 1 group, all split okay if exceeded maxInstance count limit. THe mods also include allowing batching with custom shader chunks (as shown in the green y-view-scaled billboards when you spawn on the map).