@Forza I can confirm the behavior, all points being copied, then pruned to target retention...
for now it seems to not be a bug but a feature, to not have to think of what happens in the source job in smart mode (VM added/substracted to the source job)
"we copy all and see afterward"
but @bastien-nollet and @florent can confirm on that ?
ps: I had this on mirror incremental backup, as I do not do full backups.