Major Currently MSA & MCA editors do not visualize focused sequence.
Instead of it both views use selection visualization to show selection and focus.
It works good for single item selection but makes impossible to say which row is focused (current) now and which is selected only when multiple rows are selected.
Because of it user can't predict the result of his actions from the current UI state.
We should implement separate visualization for focus state in both editors and align selection actions with the focus state.
The simplest implementation for the focus state can be a dotted rectangle around the focused sequence.