My suggestion would be to use something that points to the contents in the naming convention. For example, you could take part in the name of your project and transfer it to the name EDMX. Include something that makes it less common.
I also tend to include "Ef" in my name, which I started when working on a project that already had an existing ORM.
To take Microsoft's prototype example: if your project came under the umbrella name Norwind, here is what I would name some of the files in my model project:
EDMX File: NorwindEfModel.edmx
Generator / TT file: NorwindEfDbContext.tt
Entity Class: NorwindEntities
I can’t say that this is exactly how Microsoft would have it if you downloaded a sample project from them (although I think it will be similar), but I believe that this is a reasonable naming structure and it fits my needs. The bottom line is that it pretty much comes down to the opinion and your need for a specific difference.
knoia
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