Yes I see acceptance as the goal and denial as the polar opposite. Denial is the myopic, self absorbed, contracted awareness and acceptance is the largest percievable area incapsulating that point discovered as the expanded awareness, but acceptance itself being so supreme in comparison to denial that it has no boundaries, so calling it an actual stage denies its true position and reality.
The acceptance you mention as possible playing a part in moving from restricted views to more expansive perception, is how the greater reality of acceptance is actually permeating all life and the reason why the action called acceptance is really just an attribute of a greater all encompasing, beyong stages or levels, reality structure. Acceptance may be considered to be one of the prime attributes of awareness, manifesting porportionally w re to the degree of awareness lived.
However our mentally accepting denial, anger, guilt or grief in a conventional sense isnt quite how the process flows naturaly and perhaps this is why we permutate the process w infinte descriptions, we work and work, try this or that adaption of some emotional understanding and yet often find that tho we have breakthrus of relief, we still arent happy, enough of the time. This is part of the same process again.
I see the 4 classicly described stages as actuating in any and all situations whether we are aware of them or not.
When we wake up in the morning, we are waking up to one of these stages, and our relation to pain determines what happens next, and next, and next, ect. All our trying is usually part of where we are stuck and our attempts to get unstuck are often just our not understanding and seeing, knowing, clearly enough, what it is we are attempting and what it is we are trying to escape.
So amidst the process of learning we find one key element which plays a part in all fields; pain. Not occupying a stageular position as the emotions, nor is it an attribute of the supreme allowance, it is a primal force evident everywhere.
Course we take pain and mentally turn it into suffering and thats our delima, because pain itself is actually just vibration XQ4plus niner, but to us here, its pain, annoying, unwanted, its too much, and since we dont accept it, we create illwill towards it, and out blossoms suffering and so the stages continue and continue and continue. Our personel selfcentered creations are potentially endless and ultimately only perpetuate illusion and suffering.
I believe when we learn to love the pain, our suffering goes away, and when we learn to work hard, everything we do is play.
One addenda, in using acceptance in moving from stage to stage.
Physically allowing our anger, our guilt, our saddness to be felt will help us to incorporate deeper views about that anger,guilt, or grief which keeps us caught, but mentally accepting these emotions will most often only feed them rather than starve them into powerlessness and non existence.
Ultimately as long as we are processing discursively we will prolong our situations, delay and confound the natural flow of learning. When we are actually physically living out our emotive situations, the deeper awareness acompaning the feeling/sensation level of things will become the arena which supplies a whole new perspective and rewardality, overseeing and diminishing the previously limiting discursive ruler. Thus the stages can flow on quickly unless we abrubt the process again by fighting it, by choosing to decide that something or some event is unacceptable.