Whilst the inbuilt editor is great, it would be useful to have a setting to replace it with standard html textarea control. My personal reason is to allow a chrome extension i have which can launch a fully featured code editor from a textarea. (https://chrome.google.com/webstore/detail/zed-code-editor/pfmjnmeipppmcebplngmhfkleiinphhp and https://chrome.google.com/webstore/detail/edit-in-zed/dpkaficlkfnjemlheobmkabnnoafeepg)
another option (less useful for general users but great for chromebook users who happen to use zed anyway) would be to incorporate the simple zedd daemon into the site itself, and provide a url to paste into the editor