Most of these can be done better by using technology. For example use an app to track IOUS .... or simply write down notes on your cell phone.
In the case of the train operators though, technology as it stands now might be a hinderance.
Notice from the videos that they go through gestures _rapidly_. Recording the action each time onto a tablet or such would be a hinderance that would only delay.
To add to your argument because I agree with you quite a bit:
A post-it stuck on the side of one's monitor seems vastly superior to any sort of app based reminder. It helps that creating the post-it and sticking it somewhere is itself a physical action that is remembered much more than a few taps of a thumb.
In the case of an I.O.U., the sensible approach is to put the note in your wallet alongside your other banknotes and other things which technically count as, or can be redeemed for, money, like coupons and cards. Ideally the I.O.U. should be written by hand by the person who owes you, so the handwriting serves as authentication.
Someone at work used to have a good portion of the screen covered in notes. In worst case she just used tape to get them to stick but most of them stuck without problem.
Also you can keep a "queue" of tasks along the bottom/side of the monitor or maybe it ends up representing some sort of pipeline and before you know it you have your own personal kanban setup.
In the case of the train operators though, technology as it stands now might be a hinderance. Notice from the videos that they go through gestures _rapidly_. Recording the action each time onto a tablet or such would be a hinderance that would only delay.