Within MText have byLine Masking with more than one line of text.

[michael.perryDM5CX]

Within MText have byLine Masking with more than one line of text.

As you see below this is quite common to have just one line that if masked

would look great. Having the entire text outline as the mask is due for this 

SMART MASKING. 

[TimYarris]

Thank you for your idea. The development team will review your idea while customers continue to add feedback and vote on it.

[ChrisRS]

You can come close to this with the Civil 3D Note.

Background masking is still by component,

You still have the problem with multiline components.

Note labels are restricted to model space.

Note labels are Civil 3D objects and thus 'belong' to the Civil 3D development team.

Mtext is core AutoCAD, belonging it the AutoCAD development team.