Okay. So the meaningful consequence is that it takes you too long to climb the cliffs. [You are stymied at the bottom for too long.] The ritual completes and Demogorgon is let into the world. Even the glimpse you get from here of its twin heads jeopardises your sanity. What do you do?
You see Joe Rival already a third of the way up, while you are stymied at the bottom. But what's this? A guide at the foot of the cliffs holds the end of their trailing rope. What do you do?
You come once more to the foot of these same cliffs. All too well do you remember the summoning of Demogorgon (and the devastation that followed), and more recently the satisfaction of hearing the cry of dismay of Joe Rival as he plunged from his dislodged rope. You lay eyes on the familiar north face. Twice, you have failed to scale it. You've never reached the overhang - 100 feet above you - which will surely test you even further. Why didn't I take that trail to the east, you might well ask yourself, those last two crucial occasions?
The first hundred feet are easy. The overhang will be very hard and you will be 100' up. What do you do?
Ah, so the answer to the question is that you're just going to arbitrarily create outcomes based on the intent of the climb. That this doesn't engage the cubes at all, and totally ignores any fictional input of capability is interesting.
Assuming here that every one of these cases calls for a check (this seems to be the case), we have to look at the process overall. The initial case is that the GM describes the situation -- here we have the same set of cliffs in each, presumably described the same, or enough so that it makes no difference. The player has declared an action to attempt to climb the cliffs. Here's where you start doing what I assume the 5e* thing is -- you do not determine if the outcome of the declared action is uncertain based on the inputs of your description of the obstacle or the content of the action declaration, but rather from a broader input of the fiction to see if you (as GM) think there's an interesting consequence to failure that stems only from this goal. In other words, the call for a check to resolve climbing the cliff is only dependent on if you can conceive of a consequence to failure that goes only to the goal of the challenge. The inputs of the fiction for how you described the cliff or what the particulars of the action declaration are have no bearing on whether or not you call for a check. The call for a check is only dependent on the goal for which the action moves towards. Okay, that could work. However, it's interesting to note that the decision to call for a check then becomes entirely divorced from the process of resolving that check. Here, the fictional inputs into resolving the check are the fiction you described as the obstacle -- ie, how challenging the cliff may be to climb -- and the details of the action resolution -- was climbing gear used, how fictionally good is the climber at climbing (this is a chicken/egg fiction/mechanics thing)? These are the inputs into determining the DC, if dis/advantage is present, etc. And then the mechanics resolved based on these inputs, not the ones used to determine if a check was relevant. These report back, and then the outcome narration isn't really based on the fictional inputs to this process, but rather subbed back to the ones used for calling the check. You've created an odd little sub-subroutine here, where you call for a check based on X criteria, but resolve the check with Y criteria, and then narrate results based again on X criteria only.
Which is fine, until we get to situations where the PCs don't have a clear understood goal, or the goal interacts with secret fiction the GM knows but the PCs don't. Like the secret door example. Here the PCs are looking for something that they hope will be beneficial to them, but don't know what that something is or what benefit they will reap. They're doing this only because a trope exists of hidden things. How do you determine what the PC goal is here and develop consequences that engage that goal? Vaguely, the goal is to find something that is hopefully beneficial. What consequences are there here? If we assume that the GM has prepared secret fiction that they are referencing, then they can look to see if such secret fiction is subject to this action and what it is, but this isn't determining a consequence from the goal like you've done with the cliff example. We can check this by noting that the answer in the secret fiction doesn't change if we go with the vague goal of finding something, anything beneficial to looking for a Wand of Meteor Swarm -- the result is already in the secret fiction so the actual goal doesn't have any real input, we're just adjudicating the straightforward tasking. We don't create a 'meaningful consequence' based on the intent or goal of the action! Now, we could, but then we do not have an prepared secret fiction -- we're No Myth-ing it -- and so we can formulate consequences based on goals and there can be different consequences for failure between the two (not sure what they would be, but for arguments sake I'm saying we can do difference here). However, now we're left with what happens on a success -- if the goal is the Wand, is it found on a success?
And, all of this wraps into why I absolutely assert that 5e is not a good platform to try no myth story now play. The reasons are clearest in the discussion of the cliffs -- there's no way to actually test goal or intent in 5e, just task. This separation, that the resolution methods do not engage with any fiction of goals but instead only the fiction of GM description and understanding of the fiction and the details of the action declaration mean that we cannot use these to actually test anything other than this task resolution. Calling for a check to resolve a goal works are the call level, but resolution doesn't work because I can only test task resolution -- there's no inputs into 5e resolution methods that address or care about goals. This goes for character beliefs as well -- I can't test a belief that you're an expert cliff climber in 5e because the answer to that is already established with bonuses and the testing is going to be arbitrary based on the GM's decision of DC, which the player does not have input into (outside of suggestion).