Not so sure I like the low heat solder connection. Maybe if it was soldered first and then put in the tube.I would like to make sure I'm getting a good solder joint. A cold joint could give you a lotta problems.
So I use naked butt connectors with solder and then heat shrink.. it's the best connection ur Gunna get, and if u can spring the extra cash for the copper ones, even better.. slim and clean and moisture proof!
I used those on friends Honda blinker redo. Those were stupid easy to use, felt strong and look neat.
Friend who has semi-trailer workshop has used those a lot, he told he has had no problems and likes them.