I have the powered tailgate on my 2022 Ford F150 Lariat. It has remote drop and close. When I'm connected to my trailer, the tailgate can’t go all the way down as it hits the jack motor. How can I open the tailgate in manual mode to only lower it part way?

 

Press the release button on the tailgate and hold the gate as it goes down. Then lift to close.

 

You can also just switch to full manual tailgate mode in the settings from centre screen

 

But will it stop at 45 degrees (or however far) like the OP is asking? I didn't think it could do that but I haven't tried it.

 

I don’t believe that it will stop at 45 degrees.
Yesterday my truck was backed into my driveway about a foot away from the upright 5” pole for a basketball hoop. As the garage door was opening I hit the tailgate open on the key fob not remembering that I was backed up to the pole. I heard the tailgate beep but it didn’t open. I pushed it again just to test it and it indeed would not open with the obstruction behind it. I would assume that it would do the same thing with a trailer back there. I have seen the question here many times about an accidental opening, looks like Ford thought about that.