Beshalach, and feeding the birds on Shabbos Shirah

In a comment on a previous post, an anonymous commenter wrote:

A great Halacha Parsha Inyan Magen Avrhom, Aruch HAshulchan,Chazon Ish. Feeding the Birds on Shabbos Shira Minhag shtus or Minhag Yisroel Torah.

I don't know what I can really add to it. It concisely summarizes the inyan, with various relevant marei mekomos. You can read about it at length in What Is Bothering Rashi, on parashat Beshalach. Also, this footnote in an article by Rabbi Dr. Ari Zivitovsky:

This prohibition is also relevant to the custom of placing bread for the birds on Shabbat Shirah. For reasons behind this custom, see Aruch Hashulchan OC 324:3 and She’arim HaMetzuyanim BeHalachah 87:8. Among those who criticized this practice were the Magen Avraham (324:7); Rabbi Yaakov Emden (Siddur, Sha'ar Hagai, no. 7, p. 371 in 5664 ed.; who called the practice “foolish and prohibited”); Shulchan Aruch Harav (OC 324:8); Kitzur Shulchan Aruch 87:18; Chazon Ish (Orchat Rabbeinu, Shabbat 201, vol. 1, p. 152); Rabbi Chaim Kanievsky (Shoneh Halachot 324:12); and the Mishnah Berurah 324:31. Shemirat Shabbat Kehilchatah (27:21) is also against it, but offers a way to avoid the problem. The author suggests that one may shake out a tablecloth outdoors (in a place with an eruv), even if doing so will allow the birds to get the crumbs. However, the Maharsham (Da’at Torah 324); Aruch Hashulchan (324:3) and She’arim HaMetzuyanim BeHalachah (87:8) justify the practice of feeding the birds. Tzitz Eliezer (14:28) notes that placing food for birds on Shabbat Shirah is an old Yerushalmi custom practiced by distinguished individuals and should not be challenged. Note that despite all those who defend the Shabbat Shirah practice, no one defends feeding the fish during tashlich.

As well as many other places on the web. This, for example, is a good writeup on plausible midrashic sparks for the custom. So what is there for me to do? One thing I might be able to do here is actually track down each of these sources and present them for reading, inside, rather than have people rely on summaries.

I'm not going to do this. However, briefly, here is the Aruch Hashulchan, Orach Chaim siman 324:3:

And that Magen Avraham, same siman:

Indeed, it may well illustrate overall approaches to halacha and Jewish practice, with Mishna Brura operating based on entirely technical analysis, and with Orach Hashulchan granting great credence to actual Jewish practice.