Hi,

In case I do:
rsync -Aaxq --delete --ignore-errors --usermap=33:44 --groupmap=33:44 user@server::backup/source/ /dest/

The result is:
# getfacl file
user::rw-
user:44:r--
group::rw-
group:44:r--
mask::rw-
other::---

Looks ok. But in case:
rsync -Aaxq --delete --ignore-errors --numeric-ids --usermap=33:44 --groupmap=33:44 user@server::backup/source/ /dest/

The result is:
# getfacl file
user::rw-
user:33:r--
group::rw-
group:33:r--
mask::rw-
other::---

It looks like rsync ignored usermap groupma for acls. Non acls rights mapping still works ok.

I would also suggest adding the --addacl would be very useful.