Andre,
Glad this was a productive interchange.
A thought re the red channel: I have found that intense reds are often a problem in flower photography. I've done two things in response. First, I always chimp using all three histograms and keep the red a ways from the top. Second, this is one case where luminosity-only contrast adjustments can be helpful. In fact, it was a loss of detail in this photo 9 years ago that led me to investigate that option:
Conventional processing with an RGB curve blew out details in the reds because my contrast adjustment was also increasing saturation.
Dan