The last סעיף & the second last
Halacha in שלחן ערוך או"ח,
the רמ"א writes "Our מנהג is not to
increase in משתה ושמחה
on פורים
קטן.
However, so to
be יוצא the ידי מחמירים who hold there is
a חיוב to do so, you should add a little extra to your
סעודה".
I am not aware of any other הלכה where the
only reason
to do so is to be identified with the מחמירים even
though
you are not exactly following their Chumra .
In the second to last Halacha in Shulchan Aruch O.Ch. The
Rema writes To increase a
little in the Seudah on Purim Katan so to
be Yotzei the Machmirim who hold
there is a Chiyuv to do so.