You're only potentially breaking all custom aliases starting with ^
Seriously though, this would be a way, people in the past have suggested others ways, like a $space construct (which I personnally prefer):
//echo -a a b $space c d $space e f
which would display "a b c d e f"
Another suggestion was a new directive, but I don't like it much because you can't use it with one liner:
alias name {
#space
echo -a this support consecutives spaces etc
#space
echo -a this doesn't
}
$space is really the best because you can alter the way mIRC parse the line directly within the line, allowing alternating between current tokenization and a new tokenization