מצות של מעשר שני לדברי חכמים אדם יוצא בו ידי חובתו
Mori V'Rabi Harav Hagaon R. Shlomo Miller Shlita said,*
"Food that the owner has a right to eat, even if there are some restrictions on them, is considered belonging to him.
Therefore. one is עובר על בל יראה ובל ימצא on לחמי תודה
being it's considered enough of לכם just by having the right to eat them (רשות אכילה)
Similarly one is יוצא אכילת מצה with מעשר שני and it is considered his just because he has רשות אכילה even though there are other restrictions on מעשר שני.
Accordingly, if one is invited to the Seder, there is no need for the host to be מקנה the Matzos to the guest. There is no need for the Matzos to completely belong
to the guest.
By having a רשות אכילה is enough ownership to be יוצא."
Since it is not necessary to be מקנה, R.S.M suggested that perhaps it is better not to be מקנה the Matzos to your guest on Yom Tov.
Doing a קנין on Yom Tov is only allowed when it is for a Mitzvah.
If there is no need to do it then there is no Mitzvah and one may not do a קנין.
דרשת שבת הגדול תשע"ט*