Cover, rosette, wall opening cover - what is the name of this part?

Hi dear forum members,

We have a downpipe that goes through the balcony slab, see photo.


We want to make a cover over the breakthrough, as a trim, around the pipe.

I have googled extensively but can't find anything. I searched for rosette, trim, clamp, cover for downpipe or wall breakthrough. Apparently it is called something else.

The downpipe is DN60. Do you have any tips on what it is called or where to find something like this? It should also be in two parts.

Matching oven/ flue pipe rosettes are already available, but not in two parts, only for threading. Since you don’t want that, what speaks against patching with repair mortar / quick cement, possibly with sealing tape / sleeve around the downpipe?

Hm, that's annoying :-(
There's basically nothing against plastering, except that the plasterer, who has to come again anyway, is being difficult and says he won't do it because it's extra work for him. And we ourselves don't quite trust that it will be straight and look neat afterwards. How would it work with the sealing tape and mortar/quick-setting cement?

Am I the only one who thinks that the breakthrough and the execution generally don't look very good? The pipe is probably new or was recently dismantled. You can see the drilling dust on the wall paint near the spacer... Dismantle the pipe and put a rosette over it. Everything else involves more effort. Twice as much if the execution is done by the same people who botched it.