Additionally, what do they do in your shul (at what point, before aleinu),
In our shul, it’s done after the last kaddish is completed.
On a side note, I find it very disturbing when people talk during the announcements. There are two problems with this:
1. It prevents people who want to hear the announcements from doing so.
2. It’s disrespectful to the person speaking. It just a simple lack of derech eretz.
Fortunately, they don’t do this in my regular shul, but I’ve seen it in other shuls and it disturbs me.
The Wolf