Arknights Welfare RS-EX-4 Clear, Challenge Mode

The Rides to Lake Silberneherze level RS-EX-4, Buffer Stop, Challenge Mode, cleared using only Welfare operators.
Again, I focussed on getting the Emergency Heaters up and running, added a little bit of block and then pounded with arts damage.
Welfare operators are as defined at:
arknights.wiki...
wiki/Operator/Welfare.
Comments and advice are always appreciated.