http://www.zotero.org/support/requesting_styles
see esp. point number 2.

Perhaps the MDPI.ens could be converted?

no, not possible - though you can try using it: You can add .ens styles in 2.0 using the style manager in the preferences.

You'll want to check the output from the imported style to ensure that it's correct.

that's the problem with endnote styles - you can't fix them for Zotero.
It's probably worth making a new Zotero style for the journal then - see the page I link to above.

Here is a list of things which I had to correct after using Zotero’s style “American Chemical Society with Titles” in order to make references consistent with the MDPI style. In other words, these are differences between MDPI style and ACS with Titles.

Reference Numbers
• 1. Author 1; not (1)[Tab]Author
• References flush left all lines, no indent for second or later lines

Books
• Title capitalization
• Edition if available
• City, Country Abbreviation
• For US: City, State Abbreviation, Country Abbreviation

Journals
• Article titles use title capitalization
• ISO4 abbreviations for journal titles
• Journal titles use title capitalization

Note 1. In case it’s helpful, a workaround for the lack of an MDPI style, if the reference list isn’t too long, is to have Zotero use the ACS with Titles style to do the tricky work of inserting the article numbers in the text and generating the bibliography in sequence. Then copy the bibliography and paste as unformatted text, and manually make the necessary corrections as above, (including restoring italics and bold). That’s best done once the reference list is finalized, but if a citation does need to be added or dropped, autonumbering the reference list will allow changing a citation without having to redo everything.

Note 2. There are known issues with capitalization of article titles, which are not yet handled well by Zotero styles, so capitalization of titles may have to be done manually anyway. http://forums.zotero.org/discussion/2496/capitalization-of-journal-article-titles-in-bibliographies/

Thanks for the quick response.
The left justification is visible in the Style Guide linked in the first post in this thread. The examples in there can be copied and pasted to confirm the #.space in contrast to the (#)tab produced by ACS with Titles. The downloadable PDF version of the MDPI Style Guide says:
"The edition number is appended at the end of the title, separated with by a coma, with the edition number as an ordinal number (1st, 2nd, 3rd, 4th, etc.) followed by ‘ed.’. The letters in the ordinal number should not be put in superscript. ‘ed.’ should not be capitalized to avoid confusion with the abbreviation for editors (that is ‘Ed.’ or ‘Eds.’)."

Note that I'm not claiming my list is complete, just documenting the things I observed while working on a particular article.

I also received a further clarification that ISO abbreviations are dealt with later in the editing process.

"About the ISO4 abbreviation, actually EndNote is also not able
to do it correctly. We have to check and correct them anyway through one
of our in-house copy-editors."