Unable to turn on filter if operation is not present in block
I'm not sure how I feel about it, it has to be tested in practice and discussed, so I'm just leaving it here.
When you select filter in block view, you only see checkboxes for operations that are actually present in that block. If the checkbox for particular operation was turned off, it is not possible to turn it on, unless you find a block that actually has that operation, which might be problematic for some rare operations. Maybe it would be better to have a "filter composer" present aside of current filter button where there would only be checkboxes (with operation names on tooltip only) and a final filter value that could then be used with account history calls. Also filters could have predefined sets, like comment-related, market-operations, witness-management, governance, account-management etc.