Cutting Nails During the Thirty Days of Mourning for Matzah Baking

A mourner within the thirty days after his father's passing, who wishes to work in kneading matzah, is he allowed to cut his nails for this purpose?

For the purpose of kneading matzah, since it is a mitzvah need, during the thirty days one can be lenient, and the order of priorities is as follows: 1. It is permitted. By using teeth or hands, one can start with scissors and finish with mouth or hands.
If this solution is not convenient, one can be lenient by having a non-Jew cut the nails,
and if it is not possible through a non-Jew, let another Jew cut them.
If it is not possible through another Jew, one can be lenient by cutting them oneself.

Responsa Chaim BeYad (Rabbi Chaim Palagi, Siman 125, letter 76): "On the eve of Passover, I permitted the cutting of nails for a mourner through another due to the concern of chametz, especially for those who eat with their hands and not with a fork, and even those who eat with a fork do not avoid fruits and sweets that they place in their mouth with their hands. This is learned from the responsa Yad Eliyahu, Siman 96, and see Ikrei HaDa'at, Siman 36, letter 55 and KS, page 162b. From this, one can learn for someone hired for kneading matzah that within thirty days he should cut his nails to avoid the concern of chametz."
Certainly, his intention is that if it is possible to permit, let it be permitted, and therefore, since for all mourners it is allowed to begin with hands or teeth, as explained in Shulchan Aruch, Siman 380, paragraph 7, and also with scissors and continue with hands, as written in Shevut Yaakov, part 3, Siman 100,
and just as for immersion in a mitzvah it is permitted through a non-Jewish woman or another Jewish woman, as explained in Shulchan Aruch, Siman 380, paragraph 7, also for kneading matzah it is preferable through a non-Jew and through another Jew if it is not possible otherwise.