Edit: I guess I am on ignore, since this will be the third time going over this...
Not exactly, again, the loot at WT4 is worthless for the 50s and 60s if you have worked on your rep. The chests in WT2 give much more rep (WT4 = 840 rep, WT2 = 1200 rep per 2 zone Helltide) so opening WT4 chests is worth very little until you get to the 70s w/ a mindcage. Only the XP in WT 3/4 really makes the difference, so you can just jump back and forth when you have the cinders.
Now I could see a situation to be in lower tier, even if you unlocked the higher one. That's mainly if you are dying all the time because there are too many mobs that are 30+ levels higher and swarming your ass because you bugged it out. Where you could handle the swarms in WT 3, you might get more XP keeping the bug up, verses it getting reset every so often because you died.
Most of my WT4 deaths were from too many people at Maiden making a bunch of shit turn into 1 shot mechanics (combined with being lazy) and people spawning a Hellborne at Maiden (which would 1 shot me most of the time). Even with those deaths, leveling Helltides was very fast and I would rather be in Nightmare dungeons as little as possible. Waiting till 90+ for leveling runes meant I could do higher NM keys, which meant fewer NM dungeons.