[anoldman]

I can't comment on your trailer specifically but I can comment on tongue weight vs. trailer weight in general. Trailers are set up with about 10% to 15% of their weight on the tongue. If that weight is reduced your trailer will fishtail on the highway, sometimes violently, and could cause you to lose control. If you feel the axles are now overloaded then adding a 3rd one may make sense. If you're doing this to lower the tongue weight then be very careful.