I've noticed that despite following statement in syntax.md#identifiers, Kotlin JVM compiler is fine with escaped identifiers with '(' in it. I've also found this checker which seems to exactly follow JVM specification
Note: for example, the following characters are not allowed in identifiers used as declaration names on the JVM platform even when escaped due to JVM restrictions: (, ), {, }, [, ], .
I've noticed that despite following statement in syntax.md#identifiers, Kotlin JVM compiler is fine with escaped identifiers with '(' in it. I've also found this checker which seems to exactly follow JVM specification