I’m wondering whether there is any chance of making progress on this issue? I think that either adding a “change case” button for the title field (as mentioned by Stefan at the top of this thread), or to transform all paper titles into sentence case on import (as requested by Brady) would be good solutions.
I find that I have to manually adjust the casing in the titles for the majority of papers that I add to Paperpile, which is quite time consuming. I understand that either of the proposed solutions would still require me to adjust the casing of proper nouns in article titles - but that would be a big improvement on the current situation.