The whole solder thing is I believe a little over stressed, How many solder on pins do our electronics
have in their connections?
It takes I believe both vibration and a lack of support for a solder joint to fatigue, support the wire, and little fatigue.
But that is just my opinion.
I rarely if ever solder myself. if a possible wet location, I'll dip the stripped end of the wire in silicone grease, then crimp with a heat shrink / glue connector. I only use the heat shrink / glue butt connectors now, the glue seems to really help from a physical strength perspective as it glues well to the insulation
so if a wire gets pulled on, both the wire and the insulation
take the load.