Standing Versus Sitting for Kiddush

משנה: הָיוּ יוֹשְׁבִין כָּל אֶחָד וְאֶחָד מְבָרֵךְ לְעַצְמוֹ. הֵיסֵיבוּ אֶחָד מְבָרֵךְ לְכוּלָּן. בָּא לָהֶן יַיִן בְּתוֹךְ הַמָּזוֹן כָּל אֶחָד מְבָרֵךְ לְעַצְמוֹ לְאַחַר הַמָּזוֹן אֶחָד מְבָרֵךְ לְכוּלָּן. וְאוֹמֵר עַל הַמּוּגְמָר. תַּנִּי סֵדֶר סְעוּדָה אוֹרְחִין נִכְנָסִין וְיוֹשְׁבִין עַל הַסַּפְסָלִין וְעַל הַקַּתֶדְרָיוֹת עַד שֶׁכּוּלָּן מִתְכַּנְּסִין. הֵבִיאוּ לָהֶן יַיִן כָּל אֶחָד וְאֶחָד מְבָרֵךְ לְעַצְמוֹ. הֵבִיאוּ לָהֶן לְיָדַיִם כָּל אֶחָד וְאֶחָד נוֹטֵל יָדוֹ אַחַת. הֵבִיאוּ לָהֶן פַּרְפֶּרֶת כָּל אֶחָד וְאֶחָד מְבָרֵךְ לְעַצְמוֹ. עָלוּ וְהֵיסֵבוּ הֵבִיאוּ לָהֶן יַיִן אַף עַל פִּי שֶׁבֵּירַךְ עַל הָרִאשׁוֹן צָרִיךְ לְבָרֵךְ עַל הַשֵּׁנִי. וְאֶחָד מְבָרֵךְ עַל יְדֵי כּוּלָּם. הֵבִיאוּ לָהֶן לְיָדַיִם אַף עַל פִּי שֶׁנָּטַל יָדוֹ אַחַת צָרִיךְ לִיטוֹל שְׁתֵּי יָדָיו. הֵבִיאוּ לָהֶם פַּרְפֶּרֶת אֶחָד מְבָרֵךְ עַל יְדֵי כוּלָּן. וְאֵין רְשׁוּת לְאוֹרֵחַ לִיכָּנֵס אַחַר שָׁלֹשׁ פַּרְפְּרָאוֹת.

MISHNAH: If they were sitting, every one makes the benediction for himself. If they were lying on couches, one would make the benediction for everybody. If wine were served to them in the middle of the meal, everyone would make the benediction for himself; after the meal one person makes the benediction for everybody, and he makes the benediction on mugmar. It was stated: The order of a formal meal: Guests enter and sit on low benches or on chairs until all of them are assembled. They are served wine; everyone makes the benediction for himself. They bringthem water, everyone washes one hand. They bring them snacks, everyone makes the benediction for himself. When they entered and lie down on couches they are served wine; even though one made the benediction on the first one, he must now make the benediction on the second one; one of them makes the benediction for all of them. They bring them water; even though one had washed one hand, he now has to wash both hands. When they are served snacks, one makes the benediction for all of them. No guest may enter after three servings of snacks.

מֵיתִיבִי: כֵּיצַד סֵדֶר הֲסִבָּה? — אוֹרְחִין נִכְנָסִין וְיוֹשְׁבִין עַל גַּבֵּי סַפְסָלִין וְעַל גַּבֵּי קָתֶדְרָאוֹת עַד שֶׁיִּכָּנְסוּ כּוּלָּם. הֵבִיאוּ לָהֶם מַיִם — כׇּל אֶחָד וְאֶחָד נוֹטֵל יָדוֹ אַחַת. בָּא לָהֶם יַיִן — כׇּל אֶחָד וְאֶחָד מְבָרֵךְ לְעַצְמוֹ. עָלוּ וְהֵסַבּוּ וּבָא לָהֶם מַיִם, אַף עַל פִּי שֶׁכָּל אֶחָד וְאֶחָד נָטַל יָדוֹ אַחַת, חוֹזֵר וְנוֹטֵל שְׁתֵּי יָדָיו. בָּא לָהֶם יַיִן — אַף עַל פִּי שֶׁכָּל אֶחָד וְאֶחָד בֵּרַךְ לְעַצְמוֹ, אֶחָד מְבָרֵךְ לְכוּלָּם. בָּא לָהֶם יַיִן בְּתוֹךְ הַמָּזוֹן. שָׁאֲלוּ אֶת בֶּן זוֹמָא: מִפְּנֵי מָה אָמְרוּ בָּא לָהֶם יַיִן בְּתוֹךְ הַמָּזוֹן — כׇּל אֶחָד וְאֶחָד מְבָרֵךְ לְעַצְמוֹ, לְאַחַר הַמָּזוֹן — אֶחָד מְבָרֵךְ לְכוּלָּם? אָמַר לָהֶם: הוֹאִיל וְאֵין בֵּית הַבְּלִיעָה פָּנוּי.

The Gemara raises an objection based on a Tosefta: What is the order of reclining at a meal? The guests enter and sit upon benches and chairs [katedraot] until all are assembled. Afterward, they brought them water and each and every one washes one hand in which to hold the cup of wine. When wine came before them prior to the meal, each and every one recites a blessing over the wine for himself. Then, when they entered and reclined on the divans for the meal itself, and water came before them, despite the fact that each and every one already washed one hand, they wash both hands again prior to the meal, so that they will be able to eat with both hands. If wine came before them during the meal, despite the fact that each and every one already recited a blessing for himself, one recites a blessing on behalf of them all. We learned in the mishna: If wine came before them during the meal, each and every diner recites a blessing over the wine for himself. If the wine came after the meal, one recites a blessing on behalf of them all. The Tosefta relates: They asked Ben Zoma: Why did the Sages say: If wine came before them during the meal, each and every diner recites a blessing over the wine for himself; but if the wine came after the meal, one recites a blessing on behalf of them all? He said to them: This is because while eating, the throat is not available. If one recites a blessing on behalf of them all, he would be forced to wait until they all had finished eating and readied themselves to drink the wine together (Tosafot). To prevent imposing upon them, the Sages ruled that there is no need to recite the blessing together.

מקדש על כוס מלא יין שלא יהיה פגום וטעון כל מה שטעון כוס של בהמ"ז ואומר ויכלו מעומד ואח"כ אומר בפה"ג ואח"כ קידוש: הגה ויוכל לעמוד בשעת הקידוש ויותר טוב לישב (כל בו) ונוהגים לישב אף בשעה שאומר ויכלו רק כשמתחילין עומדין קצת לכבוד השם כי מתחילין יום הששי ויכלו השמים ונרמז השם בר"ת וכשמתחילין יתן עיניו בנרות (מהרי"ל ושכל טוב) בשעת קידוש בכוס של ברכה וכן נראה לי עיין לעיל סי' קפ"ג סעיף ד':

10. One should make Kiddush on a full cup of wine that is not blemished, and to require all that us required for a cup for Birkat Hamazon, and to say 'Vayechulu' while standing and afterwards one says 'boreh pri hagafen' and afterwards one says kiddush. RAMA: One may stand during the time of Kiddush but it is better to sit (Kol Bo). Our custom is to sit even while saying 'Vayechulu', except when we begin we stand a bit to honor Hashem, because we begin 'Yom Hashishi, Vayechulu Hashamayim' and it hints to Hashem in the first letters of this phrase. When one begins he should look at the candles (Mahar"il; Sechel Tov) during kiddush with the cup of blessing. And so it seems to me, see above Siman 183 Seif 4.