gordo, We have sales people that will want to view press sheets in all lighting conditions (5k, office, outdoors) before OK'ing a internal press check. Usually they will adjust magenta down from standard densities and gray balance to account for office lighting and not match the proof. This is increasing press OK's and causing scheduling challenges. I am wounding if pulling magenta down in our proof and also adjust press curves accordingly could be a viable solution. If this works, we may have to give up our G7 certification.
Well you're in a pickle.
Assuming that your proof and presswork align under 5K lighting you could bias your proof and presswork by upping the Y and C which effectively lowers the M (I generally prefer increasing ink density rather than lowering it). I can't see an issue with that - unless the presswork is intended to align with some other shop's work that isn't biasing their process equally. It's still a crapshoot though because there's so much lighting variability in the field.
You could also make use of a gizmo like this:
to help educate the team (and your customers)
Some shops, if they don't have the multi-light viewing booth will have a room away from the press where sales or customers could evaluate proof/color. It would have a 5K viewing booth as well as typical office lighting so that evaluation can be made between those two.
If the target lighting is known - e.g. house brand packaging labels then the shop doing that work will often include the same lighting in their viewing area that's in the target environment.
Most proofing papers are intended to be a metameric match to the presswork under 5K - although that's also a bit of a crapshoot.
Personally, if this is an issue with all your presswork then I'd bias the press/proof.
If it's an issue with only one or two clients then I'd develop a proofer profile and print condition to satisfy their needs and use your standard for the rest of your work
In either case, I'd do some kind of education for sales/clients in order to set expectations correctly.