Pieter, I think this is a realy good idea but there is a strong chance that HP will be playing with the colour mixing, so it may be an idea to wait a while as the profiles will change if they do.
of course you are right,
That will be a change of firmware and/or print utility. That's why I ask all those that add a profile to give information on the version of the software used.
You never know how long it takes for HP to change to better- or if they can. In the mean time I need to work and try to collect all the info on paper available. It is a work in progress.
There is also the possibility the " advanced profiling solution" may be giving some improvement and other ICCprofiles.