I see we have more flexible usage of groups in the latest update but I still think there is room for improvement in that regard. Here are a few more suggestion to help please the OCD group afficionados among us.
No Keyboard focus on group headers option / mode
An option to make group headers unfocusable with keyboard navigation - so they can be interacted with only via mouse. When all groups are expanded and you need them that way - you should not be concerned about headers unless you want to click a header to select it's files. Otherwise there's a risk when going through files and let's say deleting - to accidentaly delete while focused on a header -> which would select all files under it and then delete them all..
Accordion behaviour for groups (when keyboard navigating through files)
In this mode only one group is expanded in the tab at all times - the one whose file has keyboard cursor focus. Multiselection notwithstanding. When getting to the end of it and hitting down arrow - automatically collapse it and expand the next one and start going through it's files and so on.
Here's an example of how it behaves: https://jqueryui.com/accordion
Auto expand all groups with results for FAYT filtering/selection
FAYT filtering/selection on filenames in collapsed groups only displays the group header. It should expand all related groups that have matches so they can be seen and interacted with without having to manually expand groups.
Group expand/collapse lists as folder format settings:
Folder fomats > Expanded group whitelist (listed groups are expanded, all others are collapsed) or blacklist (listed groups are collapsed, all others are expanded). Could be just a simple input field with group names separated by a semicolon.
That's all I have for now, thanks for reading.