check-spell-ec: ignore source words

I am proposing to force this behavior, however I would like feedback from people using this sieve. Would everyone be OK with ignoring words that exist in the original string? (which I believe is what Lokalize does)

Alternatively, I would expose this as a setting, and even keep the old behavior by default. In that case, however, it would be nice if someone could help me understand how I can make this setting discoverable in http://pology.nedohodnik.net//doc/user/en_US/index-mono.html#sv-check-spell-ec, if at all possible (I am not sure if those docs were generated once and are frozen now, or are actually updated from the sources).