[Remind-Fans] Best practices for multiple identical reminders on disjoint dates?

[Tim Chase]

I'd like to try and minimize copy/paste in my reminder file, so my
first stab was expression-pasting a variable something like

SET x "Check Cowboys score for yesterday's game (free coffee @Dunkin
if they won)"
REM Sep 9 2019 MSG %"[x]%"%
REM Sep 16 2019 MSG %"[x]%"%
REM Sep 23 2019 MSG %"[x]%"%
REM Sep 30 2019 MSG %"[x]%"%
REM Oct 7 2019 MSG %"[x]%"%
REM Oct 14 2019 MSG %"[x]%"%
REM Oct 21 2019 MSG %"[x]%"%
REM Nov 5 2019 MSG %"[x]%"%
REM Nov 11 2019 MSG %"[x]%"%
REM Nov 18 2019 MSG %"[x]%"%
REM Nov 25 2019 MSG %"[x]%"%
REM Nov 29 2019 MSG %"[x]%"%
REM Dec 6 2019 MSG %"[x]%"%
REM Dec 16 2019 MSG %"[x]%"%
REM Dec 23 2019 MSG %"[x]%"%
REM Dec 30 2019 MSG %"[x]%"%

so if I change the text, it updates everywhere. Note that there
doesn't seem to be much predicatable about the dates (some are
Sunday, some Monday, some Thur; there's a bye-week in there, etc).

Things get even uglier if I want to then get pre-warning (e.g. I
decide I want a day of notice so I need to add "+1" on every REM) or
need different messages inside/outside the calendar (e.g.
%"Check Cowboys score%" for free coffee%
)

Is there a more elegant pattern I should be using for such disjoint
lists of dates for an otherwise-the-same event?

Thanks!

-tim