I've just passed 550 miles and, as with every other new car I've owned, I haven't given it much thought and certainly haven't been keeping it under x rpm etc.
What I will do, and this isn't just during the 'run-in' period, is be gentle on the throttle and change up nice and early while the engine is still warming up. That's just courtesy to the oily/whirly bits though which have a tough old life.
I've seen subjective evidence at least that overly gentle use of a car during run-in can actually be bad for the long-term health of an engine.
This can be an emotive subject as people feel comfortable repeating 'home truths' about rev limits, avoiding full throttle etc., but speaking to engine builders and tuners (not just bolt-on merchants, proper developers, race teams etc.) over the years I know of failures that have occurred under 30k miles from engines that were pampered in early life (unusual cylinder wear leading to bore wash), and of 100k mile stripdowns of engines that were hammered from day zero that showed negligible wear.
All my cars have used less than the nominal amount of oil, have felt strong in use and have suffered no untoward failures of any interals or lubrication ancilleries. This includes an E-Class that had nearly 300k miles by the time it was sold and a number of Evos with over 100k miles, cars that 'pub experts' may tell you are fragile and very sensitive to regular maintenance and/or unable to cope with outputting >150hp/l for any length of time.
Small sample I know, but...
Besides, the Up makes such a fruity noise that it would be very hard to keep it under 3000rpm for 6 weeks!