In the Select widget configuration, under "Choose which layers are available to select", it is not possible to toggle off Tile layers.
![](/legacyfs/online/422827_pastedImage_3.png)
While all other layers have the capability of being toggled on or off for selectivity - if tiles cannot be selected anyways they shouldn't show up as an option in the Select widget...
I would suggest to either not allow them to show up in the list of layers to be selected or allow users to hide them from the widget.
![](/legacyfs/online/422825_pastedImage_1.png)
![](/legacyfs/online/422828_pastedImage_4.png)