Cartridge depth and advice

Hi I'm using a hummingbird gen 2 rotary with cartridges leaving the needles out to a minimum. Then I'm tending to touch the skin with the plastic of cartridge and find it easier then having the needles longer and going just off the needle any advice if this is wrong or bad practice??

it says on the hummingbird website not intended for cartridges.

the power it takes to push them takes the machine outside of it's operating range.