Itachi and Izumi lived a whole life together inside Tsukioyomi which which's time passes at a rate of 1 second compared to 1×10^-11 seconds in the real world. I don't realize if you understand this or not but this technically would be a MFTL feat as
1. Assuming they lived for 70 years, they'd walk around 250 million steps
2. We can calculate the exact distance using Itachi's height which is 5'9" and we get around the total distance as 1225100 miles that they covered in around 2.5 billion seconds of tsukioyomi time or 0.025 seconds of real time.
3. This comes out to being around 49004000 miles per second or 176,414,400,000 miles / hour or approx 223 C.
This is insane speed and considering Hebi Sasuke was capable of reacting to this jutsu, we can comfortably scale all the other god/high tiers way above this speed by like at least 100x.
Even just a 10x difference would mean that a large amount of ninja in the narutoverse are easily ftl and can blitz most db characters like saiyan saga goku and vegeta.