First of all, I thank RStrauss for the comment, which I see was also appreciated by Raffaele (at least I kill two birds with one stone).
Before talking about the introduction(/coda) at measure 4, the crescendo simply means that the second C is stronger than the previous one, followed by a "sudden" piano... what is not feasible? Two different notes can differ in dynamics and it's not necessarily true that one must write "p" on the first C and "mp" on the second.
Tantamount, in the case of re-orchestration, it would be a very clear indication for the arranger.
I was talking about the coda because, I read:
rstrauss wrote:I sincerely find the introduction in slow tempo with long notes and in empty octaves to be a bit too long. It has no connection to anything that happens afterwards and unfortunately the piano written this way doesn't really work. If the tempo had been faster, it might have worked.
The coda, on the other hand, works much better: the rallentando and the diminuendo give that sense of an ending that was needed.
I will spare you now what one of Chopin's contemporaries wrote when commenting on the Op. 35 sonata regarding the thematic and motivic development (but I will report it to you this evening). As you can see from the attachment, there is nothing more relevant to what happens afterwards than my introduction. (but also for other reasons that I am not revealing now... there will be time).
The theme is "simply" a development of the introduction and the coda. Why do I always say coda? Because you mention it in your comment, but above all because it is the "cancrizzazione" [crab motion/inversion] of the introduction that works forwards and backwards (try following the notes in the 2 verses).
Just as it relaxes at the end, it prepares at the beginning, and if it works rhythmically in one direction (as you write), it also works in reverse, especially because on the way forward (in the introduction) there is a written accelerando. It is very evident (even just by sight) the passage from semiminims to eighth notes.
Besides, whole notes that last only for 3 measures... far from 24, oh well.
In the initial register, the 4 Gs played in unison in the piano could have a duration 7 or 8 times higher than the 3 seconds required by this passage... it works beautifully, far from not working. The pf in the bass register is beautiful and, thus, one has time to appreciate all the harmonics... if you don't like them then let's call things by their name: taste. If you want, I can send you a list of dozens of composed pieces with a slow beginning for pf.
The first tempo being faster would have been something else, maybe you would have liked it more, but frankly I would have found it less musical.
A small part of what the introduction contains can be found in the attachment; only a deaf person wouldn't hear the bass reprise when the exposition arrives, wouldn't hear the theme which is already present from measure 12 (far from 24), wouldn't hear the chromaticism that starts from measure 5 in an ascending motion and will then be presented in contrary motion, diminished and in syncopation in the theme.
I read that you define it as a triviality because you find the piece excellent... this "detail" is of fundamental importance to understand the true structure of this piece.