When you click on an item the customized Power App form pop-ups from the right side of the screen.
When you tick an item and then click detailed pane it also pop-ups from the right side of the screen with the ability to edit data.
This is ok for simple forms with a few data fields but in more complex scenarios Power App form may include additional screens and logic that can not be used from the details pane.
So, users can be confused why they may edit data in both places, but in different ways?
Why not let override default details pane with customized Power App form (replace Properties with the Form)?
When using custom Powerapps Forms in SharePoint (SP) I turn off this feature in the SP list because I don't want my users bypassing the custom business logic in the PowerApps form by using the quick edit features in the SP list view. You can turn it off by going to the List Setting > Advance Settings > Quick property editing and selecting No.
Thank you @Jeff_Thorpe, this is really a good way keeping business logic in place.
Even if I turn off the Quick Edit features the user will still see the details pane with all the fields. I would like to be able to either
a) turn off the details pane entirely
b) let the custom PowerApps form be used in view mode to show the desired info in the desired way.
So I think this idea is completely valid still.