No you cannot use a MT rail on a Battue, the straight cut slot will block out of the rear sight.
You will need a EGW rail.  I have one on Battue 308 and you can use the open sights perfectly. 
The ramp of fiber optics on the rear sight is clear and in view when you shoulder the gun, does not distort your view at all.

See attached for visual reference, with the slot centres removed you can see straight up the middle of the rail.

I also cut this rail to correct receiver length, like I do on must T3 guns…