I brought a 14/3 U/F cable into a single plastic nail-on box, through a hole that I drilled through the back of the box. Do I need a connector on that wire, and if so what would you recommend a black button Romex connector backwards?
I have used listed clamps on construction boxes but black button connector is a device like an “insider” plastic clamp it is only listed for 1 direction. Mechanical 2 screw clamps can be installed with the screws on the inside or outside. On plastic boxes if you have a bushing to protect the insulation the staple needs to be within 8” not all plastic boxes have clamps but if you drill a hole it will require protection for the wire at a minimum. I would say based on that it doesn’t matter but if the instructions for your clamp provide a direction the inspector can flag it.