Hi Antonio1,
Post #2 here along with post #6 here and post #45 here may give you some insights into fine tuning and re-arranging layers that may be helpful. the first step though is always to call the manufacturer (in this case Shawn) because their suggestions will have the most direct experience with their own mattresses behind them.
As you mentioned … your body will also take some time to adjust to any new sleeping surface and “unlearn” it’s old sleeping habits (see post #7 here) so it’s also important to make sure that you have spent “enough” time on the mattress before you begin making changes and to make sure that any changes are incremental and not too many in a short period of time so you can identify which changes are connected to which “effect” and your body has time to “catch up” to each change.
I would also do some “re-arranging” before exchanging layers such as switching the firm and medium layers so the firm is in the middle as a first incremental step to test the effect of improving deep support first … but only after you have given things “enough time” with your initial configuration (I would suggest a minimum of 2 weeks if possible). This thread may also be helpful where one of the forum members has included pictures of their alignment and the effect of re-arranging layers.
Phoenix