Best way to make a passive lock for lift?

so from watching some videos of lifts and trying it on my own dumper type robot. My team’s robot can pull itself about half way up to make it a low hang( we are currently attempting to make this a high hang). The arm is 1:5 for torque with high strength gears and a 4 motor lift. first question: will making this a 6 or 8 motor lift be able to change the outcome and make this a high hang without changing the gear ratio? and how, when the robot is high hung, can the robot stay up after the power is cut(such as a passive lock)?