I recall there was research some years ago that predicted when entangled particles are measured, their wave function collapses (and entangled particles' properties take on definite values between each other) at a speed which the lower bound was supposed to be about 10,000x light speed (c). https://www.science.org/content/article/quantum-physics-gets...

But this seems to measure the speed at which particles can become entangled in the first place, which I always assumed would've been on the scale of Planck time, but 232 attoseconds is pretty long compared to 10^-43 seconds.