I have a hard tri-fold cover. I have the rear latches just loose enough for the tailgate to release. It would get stuck if I have the latch tight.
Was at Home Depot and used the remote to open the tailgate. But then I decided to just put whatever I bought in the back seat. But because I had the tonneau cover on tight, the tailgate didn't completely open, and then I forgot about it. Drove down I-80 about 40-50 miles until a guy in a Tacoma, pulled up beside me and started giving me hand signals. After a few seconds I finally understood and pulled over to close the tailgate. Luckily my bed was empty and I didn't loose anything. Since then I adjusted the latch so my tailgate would freely open.