glissando and first time play skip

Hi all.
The attached picture shows a portion of a score where the round brackets mean the notes are not played at first occurrence of the REPEAT, whereas they are played every other time.
The small line it’s a “glissando” which starts with last syllable at the end of the REPEAT.
In attempting to implement this notation in MuS, I encounter two issues:
1) I do not know how to do the glissando since I should start from a point which is not contiguous with the point where it ends, and
2) When I play it, the first time MuS does not skip the notes within parentheses
Any advice?
Thanks,