Here are a few recommended settings for Tapatalk:
Push Notifications - Enabled
Signature - Set to "ON" if you don't have one that was created via the forum settings. Otherwise, set it to "OFF".
Tab Behavior - Set it to "Forums" especially if you only subscribe to iMore or already have your forums setup to be accessed via Tapatalk. Also enable "Tab Bar in Forum". In regard to "First Tab" and "Last Visited Tab", that will depend on you. If you've re-arranged the tab to suit your tastes AND have made the tab you frequent most the first tab, then select "First Tab". Otherwise, choose "Last Visited Tab".
Unread behavior - Enabled