Value and use of \Changes@Len@summ questionable
The current value is .3\textwidth
. With a wide \textwidth this gets fairly wide, but with a small textwidth it looks even worse with some lines getting dots and other not and no alignment, e.g.,
Granted that this an extreme column width it wouldn't be impossible to have all changes inside a multicols for example.
Also the fact that the register has an internal name means that it can't be changed easily by the user.
My suggestion would be to define the register to be like the widest text entry plus a bit instead, eg
\settowidth{\Changes@Len@summ}{Highlighted \qquad}
Of course there is the problem that the text changes from language to language, so to do this properly one would probably have to measure all at begin document and use the widest of them. Not difficult but a bit boring :-)
In addition I would change the registers name so that could be set by the user (or offer another key like width
so that the user can set it).