Two single arms isolate adjustment
Independent clamps and posts make it easier to tune different monitor weights and positions, but they consume more desk-edge space and require two strong mounting areas.
A dual arm concentrates load
One clamp can simplify the desk edge, while both screens apply leverage through the same post and desktop area. Desk stiffness and clamp support become especially important while walking.
Keep screens close to their posts
Long extension increases leverage and visible oscillation. Arrange the desk so both screens can stay near the support while maintaining a comfortable viewing distance.
Test the full movement system
Check monitor weight, VESA pattern, clamp clearance, desktop construction, sit-stand travel, cable slack, and screen movement at the intended walking speed.