oops, I forgot a word in my previously answer. Is it better now Timothy ?
Yes it does.
My point, though, is that the programners and devs would have used the closest sector timing line as the DRS detection line, therefore making the distance between the detection line and DRS straight up to 1/3 of the lap length. That would also NOT make the DRS detection line hidden, considering that the sector timing lines are known points.
Devs would have done this as a best compromise to make programming easier
Considering this, in hindsught, I would agree that moving DRS detection lines to 100m before the bend before the DRS straight would be a good idea.