and if you analize the RIAA curve you can see that exist a significative compression in the bass frequency range that latter on the phono stage have to be " restablished " through another RIAA eq. degradation mechanism.
This is absolute nonsense. The RIAA curve has nothing to do with compression!
"they will send the master digital file with the understanding that the LP mastering engineer will deal with it as needed. "Yes, it is. And when the CD mastering engineer gets a hold of it, at the very least it will get normalized (which is actually a good thing), but will likely also get compressed and may see some EQ. It has to work in a car! So this is why you see the LP showing greater dynamic range.
Isn’t that pretty much what they sent the CD mastering engineer as well?