I don't know which version you are using, but for most of our product, the scale will automatic snap to the nearest zoomlevel. For the API scaleup(number) and scaledown(number), it scale a percent like 10% which based it's original scale value, you can get that in Map.CurrentScale. But if after it scale 10%, it hadn't reach the next zoomlevel, it will roll back to original value in fact.
level 1: scale 10000
level 2: scale 1000
level 1 scale 10% to level 2, it's 9000 now, it hadn't reach the special value between two levels, so the result should still be scale 10000 but not the 9000.
That means for map render, in most scenario, scaleup(10) is not useful, please call something like scaleup(70), which should looks different on map.
Wish that's helpful.