Why do I do it? When you solder all four corners you have a rigid box. Something is gonna give, probably the joint at the throw bar where the rail is half width. Harder solder isn't my idea of 'the answer'.
Steps I use.
1. Remove cladding from both sides of a switch tie. I resort to chemicals banned by the state of California.
2. Tin the inside of the point rail near the end.
3. Drill #74 holes in the throw bar. You will figure out where once you see the whole picture. I counter sink the bottom side for the pin head using a 45 degree (not #11) fat XACTO blade. I use 24 ga raw brass pins because they are soft. Pushing down on the throw bar with the pin inserted use an NMRA guage for the thickness of bending the pin. I gently whack the pin with a 1" machinists square to sharpen the bend. I position the pin bend perpendicular to the tie and trim it close to the edge of the tie leaving .060 +-. Plenty of solder joint.
4. I place a blank tie in the throw bar slot. I place the throw bar on top of that. I place the switch in the fixture on top of everything. I can slide the points back and forth as well as the throw bar.
5. Mark the points where the pins hit the points. File/saw a notch for the pins to fit into the rail bases.
6. Place a piece of paper between the point rail and the stock rail.
7. Solder the pin parallel on top of base of the point. I usually have to push with my iron very gently to get the pin in the notch.
8. It my be necessary to file a bit off of the top of the pin on top of the rail base.
This works with code 55 but your on your own with 40.