They might do, and if they do it will increase TOM. More clearway increases FLL TOM and reduces V1, more stopway increases FLL TOM and increases V1, but if the calculation assumes anything other than TODA=ASDA (or TODR=ASDR if you like) it isn't the balanced field solution. Moving away from balanced field optimises the FLL take-off mass at the expense of quick and easy solutions. In this case, if it wasn't a balanced field calculation you are right, there is no requirement to make 35ft at the end of the concrete OEI.