When using the select widget in a map with many selectable layers, sometimes finding the layer with the selection can be a time consuming process! I mainly found this an issue whilst using the Select by Attributes option, but still applies to the other Select by options too.
My idea is to include all the layers with at least one feature selected to feature at the top of the widget, as these are likely the features most interested to analyse at the time of selection. Would save a lot of time scrolling and trying to find the particular layer or any non-zero numbers!
Illustration as below:
Select Widget idea