I will tell you an idea of mine, a new feature that can help users to solve
the problem. Maybe it's silly or not doable.
Let there be a new variable to define file types (according to extension)
and the lang. env. for those file types. For '.el' files, English lang.
env. can be assigned using that variable.
That means the user will have an option to say: 'Always evaluate .el files
using English language' to Emacs.