Correct.
Pike v7.6 release 93 running Hilfe v3.5 (Incremental Pike Frontend)
String.width(Locale.Charset.encoder("utf-16-le")->feed("\x12345")->drain());
(1) Result: 8
String.width(Locale.Charset.encoder("utf-16-be")->feed("\x12345")->drain());
(2) Result: 8