In the context of templated grid cells, the combo and simple combo components should be rendered so they fit the grid cell in a more cohesive way.

Here's how a simple combo looks in the context of the grid component for a templated cell:

I propose a change to the design, similar to what we do to these components in cell-editing mode, something more akin to the following:

Note: The video also shows a progress bar being shown. This is an app scenario and the positioning of the progress bar should be handled by the end-user developer.