New mockups in the devtalk (https://developer.blender.org/T73479) include:
A selection Window/ Crossing toggle:
For box mode selection (default hokey = B), the UI should allow for clicking on the toolbar to be able to change the selection settings (note this button is already there, a select window/crossing toggle is added).
Under preferences, there could be a setting to have direction dependent window/crossing selection based on which direction is used during dragging, as is common in many CAD applications. This would remove the toggles from the interface.
A facedot overlay toggle:
A new select through button with the option for Facedot selection, turned off, it allows for area selection:
Another design task was labeled, where selection preview should be added, i.e. if a non-selected face is in front of the selection, the selection should be displayed over this unselected face. See here: https://developer.blender.org/T78482