I could find it at one point, but I'm coming up short today. I won't make up a number, but I do know that I saw no rolling shutter artifacts when I was shooting motion with an X-T3 in-store, but I did see them when I was shooting with an EOS R (shooting both with electronic shutter, of course).It's not really that bad for other than the stillest subjects, slowly walking people are often not a problem for example. Do you have a source for X-T3 readout speed, I was looking for it a while back but couldn't really find anything other than "X-T2 is x% faster than X-T1" and "X-T3 is x% faster than X-T2". A good amount of mft cameras have readout speed of 1/60s and IIRC X-T3 was slower than those.
Side note: those mfts and A9 all shoot 12bit files with that highest speed.