There are two lmtp sockets. One (unix:private:lmtp) created by postfix and one (in postfix speak: unix:private:dovecot-lmtp)created by dovecot. Postfix uses the first one internally and uses the LMTP protocol over it. Dovecot puts the second one in postfix's private area for postfix to deliver mail to dovecot with LMTP.
Ah, i get it. Viktor wasn't saying don't use the method, it was about the naming of lmtp vs dovecot-lmtp. Makes sense now, thanks.