Adding just 5 more seconds to the base clock may make it feel less like bullshit. Also, my arm is now strained, yippee.
I don't think you really entirely tested this for how it works between multiple devices and for people other than yourself, you always have to give a bit of leeway for people who don't make the game, due to hardware differences. For instance, the only reason I actually beat it wasn't by using two fingers but by stiffening my arm and to the point it shakes and jitters so I can hit the spacebar fast enough with one hand, and it was still a close call. I did this because even with multiple keyboards, trying to spam with multiple fingers would only register the press once as a hardware limitation. as well, the time limit is actually remarkably short for how much you need to spam it, considering internet interruptions as well can affect how effectively someone can play the game, especially if they hit any buttons to the side that acts as a shortcut on accident, which happened a few times as I was attempting to use multiple keyboards or even alternating my fingers. I get the idea you're going for, but on several occasions, I was right there as the clock expired