I'll give you my opinion: If you like the 109 Pro, stick with it and forget about the Elite unless you have another 3-4 grand sitting around gathering dust. I sold my Elites after buying the 109 Pro, that's how special it is.
I understand your hopefulness in thinking that since they are both Meze products, and the Elites cost so much more, that they must be "better". And in some ways they are, but honestly the dynamics, tonality, texture, bass response, and clarity are ALL better with the 109 Pro. Technicalities, detail quantity, and soundstage are really the only areas where the Elites shine, by comparison. Again, this is only my opinion after owning both.
Frankly, after owning several multi-kilobuck headphones and IEMs, I find myself more than satisfied with many various alternatives below the $1k mark. The 109 Pro is right near the top. It's just so engaging and alluring to listen to. Vocals are super clear and forward. I haven't missed my Elites for a single second since owning the 109 Pros.