Blow The Shofar Early

I saw the following suggestion on a otzar hachachma forum,  נשמע מצחיק, אך ראיתי מי שמפלפל שאפשר שבתאריך א' בתשרי יש לתקוע בשופר ורק שהלילה התמעט, ומי שקיבל תספת יו"ט יוכל לתקוע שהרי אצלו זהו תאריך של א' בתשרי ואין זה לילה.    

The Gemarah Rosh Hashana (34a) says we have a derash ביום ולא בלילה to tell us that the mitzvah of shofar does not apply by night.  The suggestion here is that if one accepts Rosh Hashana early and it is hence day, one can blow the shofar at that time.  

The basis for this chidush would seem to be based upon a number of (debatable) assumptions.

There are three ways to view tosefes Yom Tov.  One is that one has the ability to accept the isur melacha upon one's self at an earlier time but the keusha of the day only comes in when the actual Yom Tov commences.  Another way to understand is that one is able to even advance the kedushat hachag earlier and yet a third way is that the old day finishes and it is as if one starts the next day earlier with their acceptance of the Yom Tov.   This chidush assumes like the third way.  However, it says even though the next day is made earlier, it is not viewed as nighttime still it is still day ouside.   

The Rambam in Sefer Hamitzvot #170 says היא שצונו לשמוע קול שופר ביום ראשון מתשרי והוא אמרו יתעלה יום תרועה יהיה לכם.  In the heading of the Laws of Shofar in his description of the mitzvah he says as well לשמוע קול שופר באחד בתשרי.  In the first halacha he says מִצְוַת עֲשֵׂה שֶׁל תּוֹרָה לִשְׁמֹעַ תְּרוּעַת הַשּׁוֹפָר בְּרֹאשׁ הַשָּׁנָה so why does he mention twice באחד בתשרי and not just say Rosh Hashana?  Rabbi Brown (Moadanay Moshe siman 36) explains that we see from the Rambam that the mitzvah is to blow on the first day of  Tishray even if it would be lacking in the kedusha of Rosh Hashana.  We see this concept illustrated in Rashi Rosh Hashana (24a) the Gemarah says in a case when everyone saw the new moon סָלְקָא דַּעְתָּךְ אָמֵינָא: הוֹאִיל וְרָאוּהוּ בֵּית דִּין וְכׇל יִשְׂרָאֵל, אִיפַּרְסְמָא וְלָא לִיעְבְּרוּהּ, קָא מַשְׁמַע לַן. and Rashi says סד"א לא ליעברוה ואי תנא הרי זה מתקדש למחר הוה אמינא לעולם מיומא קמא מתקנינן מועדותיה, I would think although since the kiddush of the day didn't occur until the next day it is Rosh Hashana tomorrow but today is day 1 of Tishray to count toward Yom Kippur and Sukkot.  Similarly this may explain the opinion of Rashi Menachot (100b) that even though there was a Rabbinic decree not to accept witnesses for the new moon of Rosh Hashana after the mincha time ,we still count that day as 1 Tishray for counting toward the holidays even though the kedusha of Rosh Hashana is only the next day, ואכ"מ.  The Rambam would be telling us then that the mitzvah is dependent on the date of the calendar not the kedusha of the day.  This chiddush also assumes that the mitzvah is dependent on the ate of 1 Tishray, not the kedusha of Rosh Hashana.  

I don't understand why they would suggest this combination of factors when it would be simpler to suggest that the kedusha of the Yom Tov is advanced earlier but it is still technically day and therefore, one can blow the shofar. 

The Taz (600:2) discusses a case where the khal accepted Shabbas early on second day Rosh Hashana on a cloudy day but they did not blow a shofar earlier that day, can they now blow shofar after they declared it to be Shabbas?  The Taz does not assume it is the next day and therefore they can't blow shofar.

The Maharil (#33) says  ומהר"א מווינא כתב בנימוקו. ויש שאין אוכלין ביום כדי שלא יוסיפו מחול על הקדש בהאי י"ט משום דיומא דדינא הוא וכמדומה שכן הורה מהר"מ ז"ל במעגניצ"א: ועל טעם זה תמהתי דהא כבר קדשוהו בתפלה: ושמא על הכוס עיקר דהוא דאורייתא.  It may be that those that did not eat early on Rosh Hashana but may have davened early is since they hold that the acceptance of the Yom Tov early in davening is accepting the prohibitions of the day early but to eat the seudah of Yom Tov requires accepting the kedusha of the day early and that they did not want to do so as to not extend the day of judgement (It is צ"ע for Yom Kippur is the source of adding to a holiday and that is adding to a day of judgement.  See also גליוני הש"ם יומא פא that asks many questions on the Maharil.)