Hello again Sean,
So - I'm continuing my deep dive into this print volume issue.
Now - a couple things you mentioned. As for the cutter - and you mentioned - "in upper right front frame corner" - did you maybe mean upper Back corner? I believe THIS is the unit you speak of - which I circled in Red:
I did play with it - and see how it swivels - and obviously connected via a single screw. And you mentioned it's easy to remove. But, I'm going to hold off on removing it for the moment - you will see why...
Now - when you wrote "seems the smallest area you can print" - I think you meant the Largest area I can print. And, for specifics - you mentioned "is about 240x240". However, I did some experimentations. I kept on Tweaking the overall size of the Block on the build plate. And, as I would change the size - I would move it - so it didn't keep giving me warnings of Off build plate or In the Extrusion Exclusion area. When doing so - keep in mind, I did NOT change that Printer setting of Excluded Bed Area - as it still is set to:
As it turns out - I carefully kept resizing and shifting the position - as I was able to fit it within print volume - even though the size of it was 246mm x 257mm! This is it's position in back left corner of build plate:
In that pic - you can see not only the Dimensions of the block - but, the actual X/Y position of it. I was rather Thrilled to make this happen.
So - the VERY Specific exclusion area - is actually based upon the Cutter that you spoke of. And, the image on the virtual build plate actually Show the exclusion is a Cutter - with the Knife like image. In this pic - I put in the Red line to show the edge of the exclusion and where I pushed the right edge of the block unit:
What I might actually do is print that block - but, only the perimeters - NO Infill - NO Top or Bottom - and just do like 1 layer of 3 perimeters as a Test!
I will keep you all posted on the outcome!
-K