I actually have a couple of those scopes (one still in the box) and they perform quite nicely for this particular task. Check out a couple of posts and you’ll see it displaying side-by-side the same signal with my nicer $300 Rigol scope…
At this point I was testing a mini-Rambo board… using the remapped fan controls M106/M107 to provide the PWM signal for laser intensity control. This earlier post in that thread shows what the PWM signal on a RAMPS board looks like for various M106 Sxxx (where xxx = 0 - 255) commands… and how the duty cycle (ratio of time ON to total period) determines laser intensity. That signal is how it should look… regardless of the board used.