diff --git a/.github/workflows/blink_parity_mautic.yaml b/.github/workflows/blink_parity_mautic.yaml
index c18b354024..3f61d1805c 100644
--- a/.github/workflows/blink_parity_mautic.yaml
+++ b/.github/workflows/blink_parity_mautic.yaml
@@ -95,7 +95,7 @@ jobs:
             - name: Compare the two trees
               run: |
                   # ratchet gate: fail once the differing share crosses this; lower it as parity improves
-                  MAX_DIFF_PERCENT=0.6
+                  MAX_DIFF_PERCENT=0.5
                   total=0
                   differ=0
                   differing_files=""
diff --git a/blink/internal/fixer/rules/method_argument_space.go b/blink/internal/fixer/rules/method_argument_space.go
index c0bdc238ac..08313d7c97 100644
--- a/blink/internal/fixer/rules/method_argument_space.go
+++ b/blink/internal/fixer/rules/method_argument_space.go
@@ -403,7 +403,7 @@ func reflowMultilineArgs(s *tokens.Stream) bool {
 		if closeIdx < 0 || !argListIsMultiline(s, open, closeIdx) {
 			continue
 		}
-		if !isCallOrDeclParen(s, open) {
+		if !isCallOrDeclParen(s, open) && !isGroupingReflowParen(s, open) {
 			continue
 		}
 		if sigNext(s, open) == closeIdx {
@@ -416,6 +416,19 @@ func reflowMultilineArgs(s *tokens.Stream) bool {
 	return changed
 }
 
+// isGroupingReflowParen reports whether the "(" at open is a grouping parenthesis
+// after a boolean operator ("!(", "&& (", "|| ("). php-cs-fixer's MethodArgumentSpace
+// processes such parens like an argument list and, when multiline, breaks the first
+// operand onto its own line.
+func isGroupingReflowParen(s *tokens.Stream, open int) bool {
+	p := sigPrev(s, open)
+	if p < 0 {
+		return false
+	}
+	t := s.At(p)
+	return t.Kind == token.Punct && (t.Value == "!" || t.Value == "&&" || t.Value == "||")
+}
+
 // isAttributeComment reports whether t is a "#[...]" attribute (the lexer keeps
 // it as one comment token), as opposed to a "//" or "#" line comment.
 func isAttributeComment(t token.Token) bool {
diff --git a/blink/internal/fixer/rules/method_argument_space_test.go b/blink/internal/fixer/rules/method_argument_space_test.go
index 409f3961d7..3e1fd66dfd 100644
--- a/blink/internal/fixer/rules/method_argument_space_test.go
+++ b/blink/internal/fixer/rules/method_argument_space_test.go
@@ -23,6 +23,10 @@ func TestMethodArgumentSpace(t *testing.T) {
 		{"newline only inside a nested arg is left alone", "<?php foo($a, [\n    1,\n]);", "<?php foo($a, [\n    1,\n]);", false},
 		{"trailing comma before paren", "<?php foo($a,);", "<?php foo($a, );", true},
 		{"blank line between multiline args is preserved", "<?php foo(\n    $a,\n\n    $b\n);", "<?php foo(\n    $a,\n\n    $b\n);", false},
+		{"grouping paren after ! breaks after (", "<?php return !($a\n|| $b\n);", "<?php return !(\n    $a\n|| $b\n);", true},
+		{"grouping paren after && breaks after (", "<?php $x = $a && ($b\n|| $c\n);", "<?php $x = $a && (\n    $b\n|| $c\n);", true},
+		{"single-line grouping paren left alone", "<?php return !($a || $b);", "<?php return !($a || $b);", false},
+		{"control-structure paren is not reflowed", "<?php if ($a\n|| $b\n) {}", "<?php if ($a\n|| $b\n) {}", false},
 	}
 
 	for _, tc := range cases {