Allow break after [id] inside todo and margin
Rationale, if the margin is small and the id longer forcing the first word on the same line looks ugly, eg!
Bildschirmfoto_2018-10-31_um_18.33.16
Possible approach
\todo[color=authorcolor!10, bordercolor=authorcolor, linecolor=authorcolor!70, nolist]{\textbf{[#3 \arabic{authorcommentcount}]}%
~%
%FMi
\hskip 0pt plus1fill\relax
\penalty50
\hskip 0pt plus-1fill\relax
%FMi
#1}%
}%
which fills the line with space if the break is taken.
Edited by Frank Mittelbach