I have another question, is there a way to make the dialog text in the top right larger?
Axem's Scripted Message gauge works pretty well for that in many regards. It adds a transparent black background to the messages and types them out.
Also, mv_root-hdg is the name of the HUD.tbm in case you did not know. (while the HUD table is just called HUD.tbl)
The $ScaleGauges setting can help here too, it will make ALL HUD components relatively larger on most resolutions. Unless you are using a lot of custom HUD stuff this is usually a good idea to at least try.
keep in mind, setting $ScaleGauges to "yes" does not effect the Scripted Message mod's custom gauge, so if you want to make Axem's gauge bigger as well, you will have to mess with the Fonts.tbl.
Be warned, messing with Fonts.tbl is a last resort only those on weird 3 or 4 K Res screens would want, and that's only if you have the Scripted Message mod and $ScaleGauges enabled. $ScaleGauges should remove that need anyway.
If you do this, you will want to resize the image "messagebox.png" Axem's mod comes with, As the script is programed to contain text within the image's area.
Hope this helps!
EDIT: you can also use the .CFG ScriptedMessage comes with and move it to any part of the screen!