The LFM 20 is only UL rated to control lighting fixtures, not as a garage door controller. I know a lot of DIY people don’t care about stuff like that, but using it does potentially bypass safety features that the lift manufacturer may consider mandatory.
As an example, UL’s 325 standard requires that any controller that operates in remote mode (where the person is likely out of sight of the door) trigger an audible beep before the door starts closing.
Use of a trip relay that bypasses the control panel will not cause the beep to trigger.
The manual lock bypass is similar.
Unless your insurance company, township, or homeowner’s association requires a UL certification, it’s an individual choice if you want to bypass the panel.
But companies like Chamberlain don’t exist because it’s hard to make a garage door go up. They exist because it’s hard to make one come down safely. And to maintain perimeter security.
Just sayin’ 