Interactive render window dimensions...how to lock it?

how do I lock the interactive render view to the dimensions of the final render?
If I have say a 200x800 dimensions, it doesn’t fit the window to it…

this is not yet implemented, but already planned

My work arround is to to start a normal render with a resolution that fits your monitor, 1:1. There you will have your aspect ratio. Then stop the render and start an interactive session. As the vfb already fits I won’t redimension and you will have your aspect ratio in the interactive session matched. Hope this helps.