I have pondered your answer. Yes I see what you mean when you say I am trying to avoid 2 forms of discomfort, either the discomfort of urges or the discomfort of deprivation.
I guess the truth is no matter what I do I will have to experience one or the other of these. However it feels like urges can be physiological, they can be put in the circumstance line while deprivation is a feeling caused by our thoughts.
I think your advice is good to be prepared to experience both of these things if needed. Even without planning exceptions I can still experience an urge when I see the cakes on display at the grocery store. And when there is cake at work for someone’s birthday I can experience the feeling of deprivation.
Allowing those emotions and sensations to be there will be my plan.
But I also would follow the other advice in scholars which is to choose your thoughts. I can practice thinking ‘it’s not fair I can’t have cake’, or I can practice thinking ‘my life is so much better when I don’t eat cake’ if I find both of those thoughts believable the second one will bring me more peace and better results.
I know I am not powerless when it comes to the added urges I will experience if I have an exception but I also do find managing them challenging and distracting. The last time I planned to eat sugar I baked a cake and ate 3 slices then I spend the next week managing continual urges. I got to the other side of that after a couple of weeks now I just don’t want to invite that back into my life. No slice of cake seems worth it.
But I guess the secret is still to know that I can do it if I choose.

I’m not really sure why I am still posting about this except that it still doesn’t seem resolved. Maybe I am just indulging in confusion about it so I can’t move on to other matters. Or is there something I am still missing?