LZH actually remains very common in BIOS images, probably because of its superior compression in relation to the other formats along with its low implementation complexity.

See this article, for example:

http://www.intel.com/content/www/xr/ar/support/boards-and-ki...

The file it references can be downloaded here:

https://downloadcenter.intel.com/download/8375/Logo-Update-U...

...and it's somewhat amazing that it contains the original LHA.EXE from 25 years ago:

    LHA version 2.13                      Copyright (c) Haruyasu Yoshizaki, 1988-91
    === <<< A High-Performance File-Compression Program >>> ========  07/20/91  ===