Until now, I have sent mail to linux-kernel using an unmodified version
of Ximian Evolution with PGP sign turned on. 

However, I've noticed that this causes the message to contain some
escape codes that, after reading a few RFCs and the source code, turn
out to be caused by the fact that Evolution, in compliance with RFC2015,
sends PGP-signed bodies as quoted-printable unless they are already
tagged as base64. 

The rationale is that quoted-printable avoids any modification by
gateways that would obviously cause the signature to be invalid. 
However, both the cs.helsinki.fi archive and Linus' scripts (he is
quoted in the L-K FAQ saying that he only wants unmangled text/plain) do
not properly support MIME transfer encodings. 
Furthermore, if a gateway modifies a message, patches should also be
adversely affected, so this shouldn't be a problem.

Thus, among the possible solutions, the best one (and the one I'm
currently using, by patching Evolution) appears to be violating the RFC
and sending as 7-bit rather than as quoted-printable, risking
invalidation of the signatures by gateway modifications.

Not using digital signatures is obviously not an option since there is
no way to prove that a message was not authentic (if it contains a
trojan patch, for example). 

Is this solution the best/recommended one? 
Shouldn't this be added to the FAQ?