In Proton Mail, when adding or modifying a Filter the update time is extremely long. I often need to make an update and then check back in the next day to see if it has worked. I get that it's doing some reindexing or something but these update times are absolutely awful and make working via filters extremely cumbersome.

While we're at it, improvements to the filter add/edit UI would be great. Comparing to GMail, I can type in a search of my inbox and then just "turn this search into a filter" pretty easily. In Proton, I have to navigate to the settings and then create the filter and there's no ability to test-see what emails would/wouldn't be hit by the filter (which makes sense since the update time is so long that such a feature could not exist until that is dealt with.