John Kitchin has another video up in his Scimax series. This one is about how he handles spell checking in Scimax. As I watched the video, I thought that his setup was really new and different but it turns out that it’s all built on top of flyspell and Aspell with some help from flyspell-correct and flyspell-correct-ivy (included with flyspell-correct).
Watch the video to see how it all works. There’s no reason you can’t integrate Kitchin’s system into your own. There’s not a whole lot of code involved as you can see from scimax-spellcheck.el. The hydra that he discusses in here.
The video is 7 minutes, 23 seconds so it should be easy to fit into a coffee break.