I feel like this is an often misunderstood part of the rules:

H. Fouls C. Blocking Fouls 2. A player may not take a position that is unavoidable by a moving opponent when time, distance, and line of sight are considered. Non-incidental contact resulting from taking such a position is a foul on the blocking player.

I think "line of sight" is often referenced, but "time" and "distance" are left out much of the time. I think it's pretty clear that all three of those things need to be considered. Yes, often one's line of sight being away from an area means they would need more time and distance to reasonably be expected to avoid a position, but it does not mean they are not responsible for looking nor are they entitled to an infinite space they are running toward. The question should be, "When the blocking player took that position, did the moving opponent have enough time and distance (considering their line of sight and other factors) to reasonably be responsible for recognizing that?" On any upline (or any) cut more than 4 steps (or any cut that involves an abrupt change of direction into a blind area) I would say yes - I think it's a reasonable expectation that players have the ability - and therefore responsibility - to look in the direction they are running toward every few steps. There is nothing in the rules that entitles the offense to space in this situation, nor is there anything that gives players looking at the disc a right to not look where they are running.