Boron is not particularly ...

Boron is not particularly well rejected by reverse osmosis, or forward osmosis, unless the feed conditions are correct (i.e. >9.5 pH), thus other ions that might fall out of solution in high pH water must first be conditioned out.  Ion exchange is not extremely efficient, although under the right conditions you will experience fair to good results.

Possibly the best removal of boron is by total evaporation, so I would consider using vapor compression evaporator for the 7 cubic meter per hour flow you mention.  You will have to make arrangements to have the brine from your evaporator impounded, then haul it away, possibly to a deep injection well, or a salt lake where boron is already higher than in your brine.