if you cant resize the window to fit the vst, then please,
change this:

 
to this:

 
it may be nitpicky but i feel as though i am looking at beta plugins whenever they pop up. the VKFX Delay looks even worse.

I could be entirely wrong but I think the third party plugin is responsible here not Sonar. What does it look like in another DAW?

im pretty sure its sonar. the header section (preset info, solo, auto read/write, keyboard focus) requires a minimum width set by sonar, and will not adapt to a smaller sized plugin. 
 
the plugin window in Pro Tools (which also has a DAW header section) will at least center the GUI when faced with the same issue: 

 
in Logic I believe the host controls actually compress into a drop down menu to adapt to the plugin size:

 
  
Sonar looks like it just couldn't be bothered. 
 

Sorry to check (not accusing you of anything here) but...

all of these are VST3 instances like in the Sonar example? These are actual images not doctored example like you gave in the second Sonar image?

no, they wont be VST3's as Pro Tools uses aax, and Logic uses AU. only the 2nd sonar image was a mockup, the others are pulled straight from the web.
 
 
Neither Cubase nor Ableton, which both host vst's , exhibit the same redundant space as Sonar. The format of the plugin doesnt matter (vst3, vst2). This is a problem with the host.
 
Here is an example of the VKFX Delay vst2 hosted by Bluecats Patchwork (loaded in sonar) and the same plugin loaded direct into Sonar:
 

 
It just looks ridiculous, and takes up more than double the necessary screen real estate.
I understand there is functionality in the host header bar, but it could could easily be displayed over 2 lines like the previous host examples, or better yet be condensed like Cubase has done.
 

You mean like this?
 

 
I know it would be more elegant to see the entire toolbar, and I get what you're saying about having it on two lines, but as automation can be enabled in the track and you can load presets (how many people use .fxb?), then the only significant functionality you lose by trimming the right side is the "give all keystrokes to plug-in" button.
 
When I want to make plug-ins go away, I just use X-Ray.

visually yes, except manually dragging the window to size is just a temporary solution for only as long as the plugin is open. for those of us who mostly rely on plugins for 100% of our sound creation, and are constantly in a state of mixing and sound design, they get closed and reopened constantly. 
 
its a small request, but the unfinished look rubs me as unprofessional every time i see it. at least center the plugin
 
any news on official feature request submissions? they have been down for a while. 

perfectprint
visually yes, except manually dragging the window to size is just a temporary solution for only as long as the plugin is open.

 
Ah, I see. I don't run into this often because I tend to either minimize, use X-Ray, or dock larger effects so I don't open and close a lot.
 

its a small request, but the unfinished look rubs me as unprofessional every time i see it. at least center the plugin.

 
Agreed, that would be more aesthetic if you don't habitually minimize/X-Ray/dock.
 

Any news on official feature request submissions? they have been down for a while. 

 
Don't know...I'm not in the Boston office but I can ask.