It is because we don't have a function named md5_string_utf8. I see that GM:S has md5_string_utf8, md5_string_unicode and md5_file. Maybe we could add those, but right now there are no md5 functions in ENIGMA. Buffers like they are in GM:S are also unfinished as there was little interest in them.
I will see about adding MD5 functions. I don't think the output needs to be 100% exactly the same as GM:S ones though (as I'm not sure how they exactly hash utf8 and unicode for md5), but they need to be the same for binary input (files) and ASCII. In your example it seems it uses the hash for a keymap? I think that can be recoded to use something else (also, we already support key mapping).