How to handle content with encoding UTF-16 with BOM present?

[PikachuEXE]

I am using this library to download remote text files
Some of them contains content with UTF-16LE (instead of usual UTF-8) with BOM (\xff\xfe)
And directly handling the downloaded content would causes error reported in
https://bugs.ruby-lang.org/issues/16402

Is there a way in this library to handle the encoding/BOM issue properly?
(Without resorting to write to temp file and read again with different mode)