High Beams Brighter When Pulled Than When Switched On

You could use a rely that gets it activation power from the high beam wire at one headlight. Once the relay activates when the high beams are on, you would supply power thru the relay from the battery to the low beam side. This would power both beams plus give you he low beams only for oncoming traffic. I have never done this (do at your own risk) so you would want to check out the part of applying power to the low beam side because that would also put power in the hi/low beam switch from a different direction. I have used this method on other vehicle lights, just not headlights.

Always use caution in doing wiring on a car......

In my wiring, the high beam load is only changed by the low amount needed to activate the relay. The low beam then gets a new supply wire from the battery that is only used when the lights are switched to high. When low beam is needed, it reverts to the original wiring.