Thinking back (way back), the bike shop I worked in as a kid lead soldered nipples on, later on as a teen working at a surgical instrument firm we did silver solder nipples onto stainless cables (they were used as a sort of third hand nokon knuckle arm) but obviously they didn’t go thru as many stress cycles as a brake cable, and cable replacement was just part of the maintenance of them, also the flame was well ahead of the nipple and the silver flowed back a fair way