Is there a good reason to not Unix-style mangle your From line in an SMTP email header?

For context, I've been looking at several examples lately of ways to properly send email potentially containing UTF-8 characters to email addresses also potentially containing UTF-8 characters from Python 2.7 using smtplib.

One thing I came across in a few examples was people electing to use an email.Generator object so that they could override the default From header mangling behavior. My understanding is that this mangling behavior (converting the From header from "From" to ">From") is in place in order to ensure compatibility with various Unix systems. (I enjoyed reading the ranting explanations of this mangling behavior from the Unix Haters mailing list, for anyone interested in the reasoning behind this behavior).

According to the Python 2.7 docs on generating MIME documents, mangling the From line in this way...

[...] is the only guaranteed portable way to avoid having such lines be mistaken for a Unix mailbox format envelope header separator

So, I want to know if there is a good reason to adopt a practice of not mangling the From header as best practice. Does anyone have any experience with this?