Yes, we often have the same completion jump from 0% to 100% which I agree can be quite jarring.
If you are in V19 I suppose you could use a combination of an activity completion report and use that to show your learners their progress via the reporting block and the course completion block.
For the reporting block it would require multiple blocks and a saved report for each completion required and then displayed again based on audience.
Not sure if that activity report can be graphically displayed though.
And it does seem like a lot of work.