[Avodah] davening speed -tircha d'tzibbur vs tircha ha-aveilim

[Avram Sacks]

A common refrain that I hear in response to my pleas for shlichei tzibbur
to slow down is that it is a tircha d'tzibbur to go slow. But, among
nearly all shlichei tzibbur at our shul, very few go "slow." Rather it
is fast, and more fast. After witnessing yet another ma'ariv where
one of the current regular shlichei tzibbur with chiyuvim finished the
shmoneh esrai and went into kaddish shalem while I still hadn't reached
shma koleinu, I began to wonder about this issue of tircha d'tzibbur and
davening speed. Aside from the issue that it is not really possible for
most people to whip through the shmoneh esrai in less than four minutes
if one truly enunciates each word, the question really becomes whose
tircha is more important: that of the tzibbur to finish davening a few
minutes more quickly, or that of those who are in shul to say kaddish, but
can't because the shaliach tzibbur decided - and yes, it IS a decision -
to daven at a speed that makes it nearly impossible to properly enunciate
the words of the shmoneh esrai, much less to have any kavannah?

Stated differently, is there a halachic obligation for the gabbaim of a
shul to ensure that a shaliach tzibbur davens sufficiently slow so that
all those who are saying kaddish, are able to do so. One woman who was
present in shul this evening told me that she stopped davening shmoneh
esrai in order to say kaddish for her mother. Rather than focus on
the halachic problem of interrupting one's shmoneh esrai in order to say
kaddish, I would prefer to focus on the lifnei iver issue of setting up
such a situation where someone who is not so well versed is inclined to
interrupt their shmoneh esrai to say kaddish. The shul rav was not
in shul, but since the beginning of the pandemic shlichei tzibbur have
been instructed to not wait for the rav, anyway.

To be clear, we are not talking about an early morning shacharit filled
with those anxious to get to work, but an evening minyan or a late
shacharit minyan filled with retirees. From a halachic perspective,
whose tircha deserves more consideration and what is the source for
that opinion?

Avram Sacks
Skokie, IL