Allow higher zoom level overlay than "master" tileset tile's using ImageOverlayPlugin

Description

When overlaying aerial imagery on quantized mesh, for instance, I find the resolution of the texture to be lower than personal preference. I can reach the max zoom level of the overlay, but only when I am extremely zoomed in (almost not being able to see anything, being so close). errorTarget=1, if it helps; also tried with errorTarget=0 with same results.

My understanding is that the plugin uses the same zoom level for the overlay as the "master" tileset's current tile, and only uses a higher zoom level for the overlay in case the "master" tileset's max zoom level is reached and there is still a higher zoom level available for the overlay (and enableTileSplitting is set to true).

I personally find it to be too low, at least with Swiss dataset:
Quantized mesh
Aerial imagery

See fiddle here.

Solution

I would like to have a way to force using a higher zoom level for the overlay than the underlying tileset's tile.

I know 3D tiles work with setting errorTarget, but here I am not sure if that would make sense to have an errorTarget for the overlay as well.

Maybe having a zoom level offset? If zoomLevelOffset=2, for instance, the overlay zoom level will be picked at "master" tileset tile's zoom level + 2 (if the 3D tile or quantized mesh is zoom level 18, it will overlay the tile with zoom level 20 imagery).

Alternatives

None. Living with it :)

Additional context

I have much better overlay resolution using TextureOverlayPlugin. Live demo available here. Look for "Vevey" in the search bar top right to see the same location as the fiddle. Screen capture:

Start with ImageOverlayPlugin and trace how the master tileset zoom level, errorTarget, and enableTileSplitting determine the overlay tile. Reproduce the Swiss quantized-mesh and aerial-imagery example from the linked fiddle, then define the smallest configuration that permits a higher overlay zoom when imagery is available. Done means the overlay can use the requested offset without breaking existing tile selection.