Say that you divide 500 grams in 6 servings (84ish grams each), you only need to print 4 lines on the package. You can do it either externally if the packaging is transparent, or you can even do it internally if it's not (like a carton Barilla box).
All you need to do is to empty it till when vertical it reaches levels at around the next line.
I was thinking of something like a sugar dispenseur (turn the container to fill a volume, and this volume becomes you serving), but your solution is way more economical and space efficient.
I myself thought of a solution similar to yours, or even more complex solutions like revolving doors or having an internal chamber the size of a serving with two lids that can't be both open at the same time..
But to be honest, I don't think any of this is really useful beyond a restaurant where sizes are fixed (and indeed use pasta-specific ladles to have standard portions). Depending on the day of the week or how many and who's at home I'm still better doing the math with a scale than predefined servings.
Similar thing on UK butter - on a 250g block, there's 50g markings[0] on the wrapper to make simple(ish) weights easy.
[0] https://www.reddit.com/r/mildlyinteresting/comments/11ogzqj/... (only decent photo I could find on the webs and we don't currently have any butter in the fridge)