Try a lower fixed derate from the N1 LIMIT page. This will reduce Vmcg.
- and what does that do for V1?
My (old) perf manual conveniently ignores the problem in the 'text' (while the Boeing QRP says adjust V1 to Vcmg.) but allows for V1 to be raised to Vcmg when operating 'outside the tables' (?uncontam?).
We are getting back to the old days, I fear, of Vgo=Vcmg and Vstop=V1 and in between, well, you hope it doesn't happen
I personally think 698 is correct - ie 'don't go (routine) flying'. Maybe a question to your ops department, elcol? They need to take account of 698 in their manuals.