I'd really love the option to disable all "code clean up". It's more often the source of issues than the solution to problems in the context of coding HTML e-mails as there's a lot of code that's considered superfluous or incorrect by WYSIWYG editors but that's really necessary in order to have the widest array of e-mail clients render your e-mails correctly. The recent WYSIWYG upgrade, for instance, broke many of our templates, which rendered beautifully prior to the upgrade. The culprit was the new WYSIWYG editors clean up features. Thankfully we had the option to fall back to the last version of the WYSIWYG editor.
Similarly, I've been trying to apply a change to our templates to address the DPI issue in Outlook 2013. They work fine when tested in Litmus alone, but when applied to the WYSIWYG the code clean up feature appears to strip off portions of the code necessary to apply the fix properly. (Still have to do a bit of testing, but I'm fairly certain that's the source of the issue.)
.png)