Hearty congratulations on being decisive and just leaving a dishonest cult ...'' ...dismiss that which insults your soul.'' as Walt Whitman wrote.
You have done it correctly and they are already now in no legal position to interfere with your freewill exercise of your freedom of religion. With just a pen and a piece of paper you have preempted their DF DA bullshit machine.
You must never meet with them in any form of hearings or committee from this point onward.
The most recent Elders Manual 2010 warns '' Is the person willing to meet with a committee thus acknowledging the congregations authority?''
You are now free by your own hand from the day you wrote that letter - don't screw it up by ever acknowledging again the elders former ecclesial authority. A second letter warning them that any announcements respecting your name will be grounds for legal action ( violation of your right to religious freedom) Lawyers have a uniquely compelling way of phrasing these matters on letterhead.
Oh, and feel free to attend public meetings if you wish, you are now a part of the community at large. Say hello to old friends and chat - it will really piss them off!
Well done young man -you have my admiration !