I'm faded & am in the "don't play by their rules" camp , though I fully understand the desire for some sense of closure.
I wouldn't worry about the possibility of elders pestering you. They all are too busy dealing with hassles in the congregation & workload from the society to spend any time chasing after "lost sheep". At most maybe you'll get a phone call & you can simply state firmly that you are working through a few issues & will contact them if you need any help. Make it clear you don't want to waste their time or your time discussing matters. You will probably never hear from them again.
As far as stopping hassle from JWs socially etc is concerned , actually when you finally leave the JW bubble , you realise just how completely inconsequential they are. They are very few in number & actual day-to-day contact is almost nil. I've had one knock at my door in the last 5 years. I've spoken to "worldly" people & they all say the same. One has never ever spoken to a JW in his life ( he's middle aged. ) I've told them about the JW concept that there is this huge preaching campaign that is rocking the whole world & forcing everybody to take their sides either for or against God's kingdom and they all state that it is pure fantasy.
What would happen with your letter to the congregation? There would be a brief vague announcement that XXX is no longer a JW & the letter would be binned or filed away. A few murmurs in the hall - a bit of gossipping after the meeting about why you left - doubtless a few wild allegations thrown into the mix. Then that's it. Everybody moves on. Frankly - nobody gives a toss. People come & go all the time. The old joke that Kingdom Halls should have a revolving door was never truer.
In a sense - not formally DAing gives you control. The society hate the uncertainty. It confuses existing JWs. Only you know the true situation. I quite like that. If they really want to get rid of you , they would need to organise a committee , get witnesses - it's all messy. And you would "have your day in court" as it were. DAing just makes it so easy for them to kick you out.
The one advantage of not DAing is that there is always the chance that a JW who knows you who is having doubts can contact you. I've had a few private emails / texts from active JWs who wonder why I left & have concerns themselves. They wouldn't have contacted me if I'd been DAd / DFd.
But as others have said - entirely up to you. Chill out , take your time ....