That swing squat rocks! To get the most out of it sit deep into that squat each time.
Don't angle the KB so far away from you at the bottom of the movement that you have to round your back to reach it.
Pause each swing squat in the bottom of the move for a count.
No stinkbugging. No swag-backing.
Alt for the side plank is: raised hand on floor, feet unstacked.
Press low back into floor during leg hold. Use hands to rock pelvis "back."
If it is poor weather where you are, switch the run for 1 min cardio. I suggest plate switches.
Which is the best kind of switch? See vid (R).