[Avodah] saying kaddish together

[Eli Turkel]

Several people in my shul (including myself) are having an argument
with our rabbi.
Our rabbi is pushing allowing everyone to say kaddish in their own
nusach and to wait
for the longest version. The rest of us insist that everyone should at least be
encouraged to use the nusach of the shul (sefard-chassidic) though it should not
lead to fights.

I know of many poskim including RMF that insist that everyone should
say the kaddish
in unison and the same nusach. Does anyone know of any teshuvot that lechatchila
allow a variety of nuschahim to be said for kaddish?

-- 
Eli Turkel