Here you'll find things I've tinkered with. For now it's just got the one but I'll have some more up eventually.
1 4chan Dump Prepper
For the especially verbose poster. Whipped this up since the twintail volume summaries get high up into several tens of thousands of characters so this would be make things easier for future spoiler dumps. It'll tell you how much you have left and how much you're over the limit and you can put in a comment at the top to remind you if you have to do something particular for that post like say uploading an image. You can click copy to get the text onto your clipboard ready for pasting and click remove to get rid of the boxes you're done with. Just be careful no to refresh or it's gone for good.