can you please stop removing these on the ground verificable letter box tags?  It looks like a tool marks them as unknown, so you remove them. That isn't fixing. Also it would help to use a better changeset comment, only "fixes" says literally nothing.

For example you could write "removed letter_filter tag because its '...' . ".

Also when the change is still wrong then, it would get much easier to review then.

thanks, Tatfahren