None I can see.
You are asking if you can do this. I can't tell what your abilities are so I can't answer what stopped you.
-> But at 800 meters you should know this is going to be problematic. You could try it, fail so you convince your boss to go get the real link products for the distance.
That is, many will not accept that it rarely goes over 100 meters and at 8 times this you might be in some situation they won't believe you till you try it.
Hint? I would never try this over 100 meters. I've already been done that road.