That's a tough one - I called 6 or more CS in my area and as soon as their admin staff said the CS would not sign off the form without another full medical I told them I wasn't interested in their services and tried another. Eventually I found one who was willing to fill out what I needed (only parts 1, 2, 4 and 7 with vacc record).
It's unfortunate the CS you saw didn't make it clear that they wouldn't sign off the whole form from the beginning of the process - if it were me, I would've argued paying their fees based on that fact. I agree it is confusing in the wording on the form and the instructions for a K-1 visa. I'm not sure if the ambiguity allows for CS to use it as a money grab or they just don't care to take on the liability. Besides calling around and finding another CS who is willing to read the requirements and comply, I wouldn't know what to recommend to you. You could try sending in what you have, with an explanation but the way I read it is that section 4 must be signed. Wish you luck!
