Arknights Welfare BP-EX-7 Clear, Challenge Mode

Path of Life level BP-EX-7, Gene Bank - Hall of Everything, Challenge Mode, cleared using only Welfare operators.
I found it very hard to be consistent on this level. Everything depends on getting Excrescent Carapaces in the right places and then protecting them, which can be hard because of unavailable tiles.
Still, my main strategy was to get enough Excrescent Carapaces in place to force all the enemies to go all the way around the left side and along the bottom., then place Benna for damage, a defender for block, and castors for arts damage. The clear worked this time, but there were several attempts while recording that did not work.
Hope you enjoy.
Welfare operators are as defined at:
arknights.wiki...
wiki/Operator/Welfare.
Comments and advice are always appreciated.