Here are 2 different workarounds that I've put together for really quick Heading Styles while working in the Evernote Desktop client. Both simply require placing your cursor in your text to be converted... and then hitting tailor-made PhraseExpress Hotkeys. Not pretty... but way faster than anything else you'll currently find:
1. A PhraseExpress and MS Word combo:
2. Just PhraseExpress and a PE text formatting workaround:
If anyone would like further details, just let me know :-)