I can't answer your question about F!, but as far as dining close to a hard ticktet event/party, you should plan to be done by start time.
When you make your adr for this meal the CM may or may not ask you about attending the party, so you should prepare yourself to choose a time that you will be done by party time.
A couple things have been reported with the situation of having a adr at or right before party time.
Some people report that they are denied being seated unless they have the wrist band saying they are party guests. Meaning if you aren't attending the party you can't eat close to it.
Others have reported being let in to dine and then escorted out of the park by a CM as soon as they are finished. No lingering, no shopping, nothing. They are to quickly leave. (although not rushed during dinner).
So it seems there isn't a firm policy on this issue. But to avoid any chance of not getting your adr, plan to be done by 7pm and on your way out.
Have a great trip!!