Adding new window reveals and tiling

[lagi]

I have had a new window fitted in the bathroom and need to add plasterboard either side to pack out the reveals to reach the new frame.

I have done this previously in other rooms ready for the plasterer. As this is going to be tiled, would it be ok to just leave it for the tiler or should a corner bead be fitted and plastered over first?

[m3 fitter]

add the pboard and square it up with a level, to help the tiler , no bead required..

[lagi]

Thanks, that saves a job.