MY LIMITED UNDERSTANDING IS THAT IT IS VERY DIFFICULT AS YOUR POSTS ARE SAVED ON THE INDIVIDUAL RELAYS YOU USE? IN WHICH CASE YOU HAVE TO DELETE IT FROM ALL OF THEM - 

 Yes, that’s what I’m understanding from tutorials, that could actually br a good thing, except you can’t correct typos 

 YES - I HAVE MADE MANY A TYPO ALREADY AND LIKELY WILL MAKE MANY MORE