Hello again,

We apologize for this unpleasant behavior. Currently both [Auto Layout] and [Partial Auto Layout] under [Alignment] menu do not work for model elements in Sequence Diagram we are afraid.
As you point out, those menu should be grayed out when you are on Sequence Diagrams or other diagrams that those menu are inactive for or tells you so in a message. We'll take care of this soon.

We much appreciate your feedback.

FYI, we have a few options to make Sequene diagrams look better by adjusting the lifelines.

- [Tips] Make better-looking Sequence diagrams
- Other TIPS

Cheers,
SJ