Arknights Welfare RS-EX-6 Clear, Challenge Mode

The Rides to Lake Silberneherze level RS-EX-6, Railway Crossing, Challenge Mode, cleared using only Welfare operators.
I did not find this level too tough. First I set up a kill zone with arts damage on the left side of the map. Then, I let my operators turn on the Emergency Heaters, which woke the Slumbering Mountain Burdenbeasts there, and take care of them.
Meanwhile, I started setting up my kill zone on the right side of the map. As soon as possible, I retreated some of the left side operators to open up deployment slots for the right kill zone. On this run, I did have my main guard on the right die before I could protect him with a defender and caster, but luckily, I had brought an extra guard with me, so I was able to recover.
Near the end, I had to retreat more left side operators to set up a third kill zone at the upper left, to manage the Burdenbeast that was frigid near the gate there, when it revived. It was important that I place my first kill zone medic in a way that they could also cover operators in this third kill zone, because I did not have enough squad slots to bring an extra healer.
Hope you like the clear.
Welfare operators are as defined at:
arknights.wiki.gg/
wiki/Operator/Welfare.
Comments and advice are always appreciated.