Thats my understanding of it as well.

The system isn't really meant to deal with people making large investment income - which isn't a problem since in general most foreigners making under 120k/yr (who hence the income witholding tax applies) have relatively little in the way of investment income.

As a matter of fact doesn't the dividend count as income if you are a swiss resident and bump you over 120k, thus oficially you need to file - though I am sure they are more than happy to keep the 35% "who own's you?" tax if you say nothing!

A