Further optimize jut length of middle serif of `E`/`F`. (#2482)

packages/font-glyphs/src/letter/latin/upper-f.ptl

@@ -14,8 +14,11 @@ glyph-block Letter-Latin-Upper-F : begin
 
 	glyph-block-export xMidBarShrink
 	define [xMidBarShrink serifV] : [Math.max HalfStroke ((RightSB - SB) * 0.15)] + [if serifV (Stroke * 0.25) 0]
+
+	define [yMidBarImpl y] : fallback y DesignParameters.upperEBarPos
+
 	glyph-block-export yMidBar
-	define [yMidBar top y] : top * [fallback y DesignParameters.upperEBarPos]
+	define [yMidBar top y] : top * [yMidBarImpl y]
 
 	glyph-block-export EFVJutLength
 	define [EFVJutLength top pyBar stroke] : begin
@@ -23,7 +26,7 @@ glyph-block Letter-Latin-Upper-F : begin
 			top - [mix (top - stroke) ([yMidBar top pyBar] + stroke / 2) 0.5]
 		local jutBot : Math.min VJut
 			mix stroke ([yMidBar top pyBar] - stroke / 2) 0.5
-		local jutMid : 0.5 * [Math.min jutTop jutBot]
+		local jutMid : 0.5 * [mix jutBot jutTop : yMidBarImpl pyBar]
 		return { jutTop jutBot jutMid }
 
 	define xFBarLeft : SB * 1.5