Some time ago, Bob Pritchett wrote:
When we re-write our interlinear editor for Logos 4 (no date yet) my plan is to find a way to make it available to users, too. I hope we'll be able to make several specialized editors available. I know the audience is small, but for people who care the tools are awesome.
Still no date on these "specialized editors," Logos? We are not getting any younger, you realize.