Hmmm. No, I don't post with a small cushion, I post with a great big fat cushion, but I write so slowly that it soon erodes into nothing. Alas.
Yes, I write in a linear fashion (can't bring myself to write, let alone try to pronounce linearly <g>), but I don't write
installment after installment. I just ramble on and on, and then when I post, I pick reasonable-sized chunks of story that won't erode my cushion too much while still giving my readers something to chew on.
Sometimes I tweak parts I've already posted because of stuff I've written later in the story, or because of the comments I've received, but if that happens, I don't usually change the version on the boards. I just post a different version to the archive. I don't think I've ever made changes that were so significant that the story being posted became impossible to follow as a result. If it has, everyone's been too polite to mention it.
BRs? They do everything except write the story for me.

Grammar, punctuation, style, consistency, plot, technique - you name it, they've got something useful to say about it. Even better, they do it without making you feel stupid or inadequate. Wendy even manages to do it without saying a thing - it's what she
doesn't say that gives you the big clue.
Yvonne