[Avodah] Children leading post-mussaf davening

[Chesky Salomon via Avodah]

A couple of years ago, I read on one of the halacha blogs a discussion
about children below bar-mitzva age leading the post-mussaf davening on
Shabbos mornings, particularly questioning the propriety of children
leading anything to which kaddish was attached.  I wanted to discuss
this with my Rav, but could not find the blog post again.

Does anyone recollect such a discussion?  (I don't think the discussion
happened here or on Areivim.)

--Chesky Salomon