The panel is newer than its engine. After Effects loads the host script when the extension opens, so a change to it needs the panel closed and reopened — reloading is not enough. Until then the preview updates but builds use the old code.
Playhead works even in an empty comp — you don't need a cut to make a matte. Layers stacked on the same frame, and a shot repeated over itself, only ever get one matte between them.
The layer becomes the frame with holes in it. For a plain track matte you don't need this — AE's own Alpha Inverted Matte already flips a normal box matte. This is for when the layer's own alpha has to be the holdout: Stencil, Silhouette, Set Matte, or using it as artwork.
Boxes meet edge to edge and cover the frame when the wipe ends.
As a track matte only the alpha matters, so white boxes are the safe default. This is for when you want them as artwork too.
One clip, once per panel, each framed for itself — the same performer two- or three-up rather than one picture cut into tiles. The layout is whatever pattern you have set, so Bars gives columns, Split gives bands and Mondrian gives uneven panels. Punch in sets how tight each frame is, Vary how much that differs between them, Reframe how far off centre they sit. Click a panel to choose its clip; Alt-drag inside it to reframe and scroll to zoom. Timing still applies, so the panels can build on one at a time.
Each box shows a different piece of the clip it sits on. Times at 0 keeps every piece on the moment the clip is showing; wind it up and each one time remaps to its own point in the whole source file — so one clip gives you a wall of different scenes, not just the bit trimmed onto your timeline. Built inside a precomp, so your comp gains one layer, not two per box.
Only shape layers get added. No clip is trimmed, moved, or matted — pick the boxes up as a track matte yourself.
Hit Preview to map them out.
Ready.