I know this is an old thread, But it is what I found when searching so others will probably find it too. This is not a limitation anymore. There is a way to use Devart Entity Developer without being an admin user. My colleague learned (I don't know from where), here is how:

Instead of starting the program directly through the default start menu shortcut, copy and/or edit that shortcut to be:
Target: C:\Windows\System32\cmd.exe /min /C "set __COMPAT_Layer=RUNASINVOKER && start "" "C:\Program Files (x86)\Devart\EntityDeveloper\EntityDeveloper.exe""
Start In: "C:\Program Files (x86)\Devart\EntityDeveloper"

This is definitely a killer for us as our infrastructure will not allow execution with admin rights. At the moment we're still able to do that, but it will be disabled at the end of 2021.

Back when Microsoft introduced UAC in Windows Vista, most software providers re-wrote software which required admin rights to run. By now all software should be able to run under the access of a normal user.
This limitation will prevent us moving forward with this product as we increase the size of the development team.

This one limitation is actually preventing our team of developers from buying this.