Batch edit the legend for a tile layer made up of multiple (identical) rasters

[KelleeKoenig1]

Right now, I have the ability to make an entire layer in my map visible in the legend, and I can individually select which of its component layers to turn on/off in the legend. But I'd like to either replace the legend with an image (as was suggested in another idea), or have a way to turn off all the underlying component layers that are duplicates. 

The problem I'm encountering is that my tiled image layer was generated from over 400 raster tiles with identical symbology…and now my legend in the Map Viewer is showing the symbology of each input raster (see attached screenshot). Yes, I can click on all 400+ sub-layers individually, but there are multiple tile layers where this is the case for my map. Hoping there's a better way!

[MErikReedAugusta]

You should be able to CTRL+Click the checkbox for the first item in the legend, and it'll toggle all checkboxes that are at the same level.  If you somehow have nested checkboxes, you'll have to do that once per outer layer, but to my recollection, that's not an issue that will occur for legends, specifically.

You can also ALT+Click a checkbox to turn off all checkboxes at the same level other than the one you clicked on.  I do this one all the time for switching between Aerial imagery layers in my Contents pane, but it should also work for legend items.

If somehow your legend has a mixture of duplicate and non-duplicate, though, I don't know any way other than cherry-picking on one side or the other.

EDIT: The above information is for ArcGIS Pro; I just realized I was actually reading something in the AGOL Ideas board, instead.  I'm leaving it up on the off chance similar functionality either exists or could exist in AGOL in the future, but it's likely irrelevant for the topic at hand.

Having anything remotely similar to this functionality in AGOL would be a game-changer, if it's not there, already.