Well, you know that is what the iPhone 12 is rumored to offer? A regular iPhone 12 in the 5.4" size with edge to edge.
Your thread will confuse people because there is an actual rumor that an SE+ is in the works. The new one they just issued in a + size.
I am with you though, the 5.4" edge to edge would be a great phone. The SE (2020) isn't that much smaller in physical height than the X, but it weights nearly 30 grams less. That is huge. Also, being a 4.7" screen most can reach across it way easier.