Would there be a possibility to list all the possible modifiers as a contextual reminder at the bottom (or anywhere else).
For example, when you choose the direct selection tool in Photoshop, it would list want you can do if you press ALT, SHIFT, or CTRL (windows)
see how it works in another software (competition)
I think it wouldn't hurt and would greatly simplify the leaning curve for beginners (but not only, sometimes brain farts occur!)
It take so little space, and would likely be hidden if one wanted to (pretty much like rich tool tips)
Some users come from a competitor and start their Adobe learning journey and are used to find such aids in the original software and are quite puzzled it doesn't exist in Photoshop.
Obviously it could be ported to all the apps in the Creative Suite.