I've using new composer (beta) for 2 years and Composer for emails for 15 days.

I think you must solve some things:

1. Custom click to view: Is always on, even when the user has the option off by default (classic composer respect this setting)

2. Add the option text-only as off by default or maybe give to the user the posibilitty to make always off.

3. Add an option to import an html: I recognize than the new composer is nice, but I work with several companies and all has a Marketing Agency to compose the emails, agency refuses to use the composer since they do htmls for a lot of other companies and wnat to use a single tool for all (is logic), The final usesr can import the html with a single block or html block, but they also need to add personalization from database and relational tables too, Agency doesn´t know to do that and the user do not know to do that from the code... So an import into drag and drop is really needed.

Of course, the're lot of other questions like:

Languaje, it is only in english, half plattform is in spanish an composer is in english.

Format personalization. half world use other currency format in decimals

Dynamic Content

External content (like classic composer call it directly with an url)

For the last, I think that styles, or independent settings for must to be moved to the right, there is a lot of unused screen and all commands are together