“All of Israel” is saved and turns to Jesus, the Messiah of Israel, only on the very day of him returning to earth.
That solution you provide is not going to help right now.
All of Israel is the 1/3 remnant of Jews who will survive the attacks by the nations
Zechariah 13:8-9, when the Shepherd comes again:
“And it will come about in all the land,” declares the LORD,
“that two parts in it will be cut off and perish; but the third will be left in it. And I will bring the third part through the fire, refine them as silver is refined, and test them as gold is tested. They will call on My name, and I will answer them; I will say; ‘they are My people,’ and they will say, ‘The LORD is my God.’”
Also Zechariah 14 describes God’s Battle with Jerusalem’s Foes (the Nations).