I agree having 2-3 different screens for character display (one for selected character, and one for all group members) is not easy. There should be tabs on top of the "hide/show" arrows listing associated skills/features.
Like a secondary tab in the character sheet's middle section, listing every feat and skill proficiency, and/or a "show - collapse all" button to expand/retract all informations.
Unused little spaces on top may be used like this I presume (currently placeholders ?).