Not sure; but if you have unlocked the steps where season journey is needed it obviously counts.
Like, if you at Guardian now it counted.
I noticed the small update on PTR and was awaiting some announcement. None came, but I stumbled upon this post:
Seems they are "just" doing lag fix tests.
Seems very relevant (I guess it was "another" Sever bug abuse, but ZE cleared 150 with a LoN Wiz and LoN Necro):
Impale is probably the best bet.
For 90-100, Zuni WD could also work (firebats combo), but the DPS likes to attack the "wrong" targets.
If you are thinking about seasonal solo play, bare in mind that you will have RORG buff, so you can more or less use a Unity ring as well, if damage sustain is your main need (and it might give "life" to another build you prefer to play).
So, I guess that's when patch 2.6.4 drops for EU (19:00 PM, CET).
NA maintenance starts at 10:00 AM PST today:
If we are talking about Americas CR 72 then,
NumLock Devour, hit Frozen Lands at the start of the rift to stack up defenses and just wreck mobs on the way.
Here my clear for reference:
If we talk about EU rift it is even easier (though slower) than the NA CR. Video here (first try):
If I got your question right - number of levels is preset; sometimes you have just one, sometimes 10 - depending on the size and mob density of each level. And, it doesn't matter where (what level) you kill the Rift Guardian - it will not do anything regarding chance of a goblin pack spawning.
Diablo III: Challenge rift 87 - Americas:
Diablo III: Challenge rift 87 - Europe:
NA has a kinda strange LoN set-up, even though it hasn't movement skills you kinda have to hunt elites.
EU is a pretty simple Wrath of the Wastes Whirlwind set-up.
Good luck all.
Diablo III: Challenge rift 83 - Americas:
Diablo III: Challenge rift 83 - Europe:
I did both on the first try, the NA one I should have done faster, I probably didn't Haunt/harvest enough. EU is an easy LoN set-up. Good luck
Diablo III: Challenge rift 80 - Americas:
Diablo III: Challenge rift 80 - Europe:
Americas one is a tad harder this time around. Good luck and a Happy New Year!
Diablo III: Challenge rift 78 - Americas:
Diablo III: Challenge rift 78 - Europe:
Both are a tad bit hard, but doable. Short explanations in video descriptions.
Diablo III: Challenge rift 70 - Americas:
Diablo III: Challenge rift 70 - Europe:
Neither of them is to hard, for NA one it is recommended to build up Sweeping stacks as fast as possible (for defense) and hold them through the whole rift.
Diablo III: Challenge rift 64 - Europe:
Diablo III: Challenge rift 64 - Americas:
EU one is easy, NA this time around a lot harder. Good luck
Diablo III: Challenge rift 63 - Americas:
Diablo III: Challenge rift 63 - Europe:
Both easy, done on first try. And yes, I played the EU one badly.
Diablo III: Challenge rift 60 - Americas:
Easy Vyr set-up, shouldn't have issues.
Diablo III: Challenge rift 60 - Europe:
Strange Firebird Meteor build - try to Arcane Torrent at the same time when you do meteors - as it will buff meteor damage, too.
Diablo III: Challenge rift 58 - Americas:
Diablo III: Challenge rift 58 - Europe:
Interestingly different this time around, but not to hard.
And, Pchild guide for America's if you need more details:
Diablo 3 - Challenge Rift #58 - Video Guide with Map and Elite Locations!
Necro This week!
Diablo III: Challenge rift 57 - Americas:
Diablo III: Challenge rift 57 - Europe:
Both of the rifts are some awkward LoN Multishot combinations. Needed multiple tries to do them both, mainly due to pathing. If you follow the path I took you should finish them on time but probably not break a record.
Here also the Americas guide from PChild, if you need more detailed descriptions: