Related: #59792

Here's Table layout:

It feels very clunky how the templates load piecemeal. It's particularly bad in this layout due to the reflow that occurs when the templates load.

Here's Grid layout:

The fixed height helps a bit by eliminating the reflow, but it still feels very sluggish.

To address we can add a fixed height to the template previews in table layout, and add a loading indicator which obscures the preview until fully loaded.