Question

Among the medieval authorities (Rishonim) we find a dispute about sleeping on two connected beds when one’s wife is a niddah.
There is the view of our teachers Nachmanides, the Tashbetz, and Rabbenu Yeruham.
In Nachmanides’ glosses to Maimonides’ Sefer HaMitzvot, prohibition no. 353:
“But the discussion was about their question regarding a niddah: whether she is permitted to lie with her husband in one bed, she in her clothes and he in his clothes. Even though when two sleep in one bed there is closeness and mutual warming, as in the verse (Ecclesiastes 4), ‘if two lie together, they are warm,’ and whenever two sleep in one bed it is impossible without touching, as was said there (Berakhot 24a), ‘but there are the buttocks’; and there is also a further concern of intercourse. And Rav Yosef came to prohibit it because of the concern of intercourse, just as they prohibited fowl from being placed on one table with cheese, even though even eating is only rabbinically prohibited there — all the more so here, where lying together in one bed is close to leading to intercourse. And we rejected this because there is a distinguishing factor and awareness. Afterward we came to prohibit the matter because in their lying in one bed there is closeness and mutual pleasure.”
And in Tashbetz responsa, part 3, siman 58:
“Sleeping in one bed was prohibited in the Talmud in the first chapter of Tractate Shabbat (13a), he in his clothes and she in her clothes, just as with a married woman forbidden to another man, for Scripture juxtaposed them in Ezekiel, as it says: ‘He has not defiled his neighbor’s wife, nor approached a woman in her menstrual impurity.’ Any lying together that is forbidden with another man’s wife is forbidden with one’s own wife when she is a niddah. But one can distinguish here: if the bed is designated for her, it is forbidden, as the Raavad wrote in Ba’alei HaNefesh. And likewise if it is movable. But if it is not designated for her, if the bed is wide and they do not come close to one another, it is certainly permitted, for they prohibited only closeness. But this is only seclusion, and although with other forbidden relations seclusion is prohibited, with one’s wife when she is a niddah seclusion is permitted, as stated in the first chapter of Ketubot (4a), in the chapter HaDar (63b), and in Sanhedrin (37a) they say regarding ‘a hedge of roses’: provided that she sleeps on bedding designated for her and he on bedding designated for him.”
And in Rabbenu Yeruham, Toledot Adam VeChavah, netiv 26, part 4, folio 224, column 2:
“Rabbi Shmuel in the name of the Rashbetz wrote on that passage in Shabbat as follows: But one can distinguish here: if the bed is wide and they do not come close to one another, it is certainly permitted, for they prohibited only closeness. But this is only seclusion, and although with other forbidden relations seclusion is prohibited, with one’s wife when she is a niddah seclusion is permitted, as stated in Ketubot and in Sanhedrin they say regarding ‘a hedge of roses’: provided that she sleeps on bedding designated for her and he on bedding designated for him.”
But on the other hand we find the view of the Mordechai in the name of Rabbi Meir of Ivra, brought in Beit Yosef.
Beit Yosef, Yoreh De’ah 195:
“And Mordechai wrote in the first chapter of Shabbat (sec. 238): Rabbi Meir wrote that one must be careful that if there are two beds and the legs of one touch the other, he should not sleep on one and his wife, who is a niddah, on the other, unless they place a separation between them. End quote. And from the law of the bench below, and also from Rabbi Meir’s ruling, it appears that we do not accept what is written in the book of Rabbenu Yeruham, etc.”
And so too the Rema ruled there:
Gloss: “And even if each has separate bedding, and even if they sleep on two beds and the beds touch one another, it is forbidden” (Mordechai, first chapter of Shabbat, in the name of Rabbi Meir).
Now in recent years we have been privileged to have the complete edition of Mordechai published by Machon Yerushalayim,
and there Rabbi Meir’s reasoning was clarified, and it became clear that his source was a complete mistake in the text of the Talmud and an extremely puzzling interpretation.
See there in his explanation.
And this is what he writes:
“13. When Rav Dimi came, he said in the name of Rabbi Yohanan: there was one bed in the West — and Rabbi Meir of Ivra explained it as meaning that she had one bed of her own,
but it touched his bed; and ‘in the West’ means a language of mixture. And because of this he was punished. Therefore one must be careful that if there are two beds
and the legs of one touch the other, he should not sleep on one and his wife, who is a niddah, on the other, unless they place a separation between them.” End quote.
Accordingly, what is the practical halakhic ruling nowadays? Is this ruling nullified or not?
Attached is the Mordechai:
Complete Mordechai Shabbat.pdf
 

And on the Otzar HaChokhma forum, in the thread The Prohibition of Connected Beds When One’s Wife Is a Niddah – its puzzling source
they argued that one does not change the Jewish law for various reasons.
What does the Rabbi think?