In the video below we combined Sinumerik Run MyRobot /Direct Control with a trochoidal milling strategy, all on a steel workpiece:

Material: leg. steel (11SMn30)
Tool: D=12mm
Slot width: ae=12mm (full cutter diameter)
Slot depth: ap=15mm

The process was simulated in NX CAM Robotics together with the digital twin of the Sinumerik CNC -> VNCK.
You can hear the milling process is stable and it is a good first step to be able to cut so deep in steel with a robot ????, more tests will follow in the future.