Different user rights per Frontend (e.g. Excel (R) / Web (D))
It would be awesome if one could grant users different rights per Frontend (Excel vs Web). In Theory it makes sense to treat them the same (you are either allowed to change a value or you are not) BUT in real life Excel is far more complicated and counter-intuitive to use. Especially if you roll-out to 100s of users you can not be sure if someone messes up plan figures just by analyzing them (it can happen so fast and without any notice) - typical answer: "...but I haven't saved - for sure." It would be extremely helpful to grant the users rights for analyzing with Excel (R) and plan in Web (D).
If you manage this with different logins you need twice as much licenses and also have to rely on the users to stick to the rules.