I have worked with source files and sample code shared by you and have been able to observe issues. I have added them in our issue tracking system respectively.
CADNET-720 - flr1.dwf - Will not convert at all - Won’t open the file
CADNET-721 - elect1.dwf - the “Legend” in the top right corner comes out as completely black with text unreadable
CADNET-720 - notes.dwf - Will not convert at all - Won’t open the file
CADNET-722 - int2.dwf - converts well except for the two “Notes” boxes that are completely black and unreadable. Additionally there is a lot of white space around the actual drawing.
CADNET-723 - int1.dwf - “Notes” field completely black. Additionally there is a lot of white space around the actual drawing.
CADNET-720 - elev2.dwf - opens file but fails to produce image
CADNET-724 - elev1.dwf - All the solid fills have been twisted by the encoder. Seems you have a top and bottom point reversed in your code. Additionally it opens with a lot of white space around the image.
CADNET-725 - site.dwf - Notes boxes are all black and a small amount of white space on Left Side.
CADNET-720 - sect2.dwf - File will not open
This thread has been linked with these issues so that you may be automatically notified once the issues will be resolved.