If you need more than about two drops per handy box I think you should go to 4x4 boxes and this type of cover https://productcatalog.tnb.com/fi/3/326808849.jpg
With the 4 port 106 frames to have enough room to coil the service loop in the box. I've put up to 6 drops in a handy box but had to go back after to fix it. A faceplate screw shorted a pair since there wasn't enough room to coil the slack out of harms way.