There was a similar thread on another Forum, I responded and posted this same picture. I almost always use flexible leadouts after several failures with solids. The fishing tackle shown below has handled tuna, marlin, wahoo, powerful game fish, bust up's have never happened!
Use the correct line crimps as shown and the right crimping tool ( from the tackle shop ), it crimps along the line, not across it, which, may damage the plastic coated stainless wire. Loop the line through the crimp and push the tail back through the sleeve, snug it and crimp. Snip off the excess line with the shears on the crimper.
Enough material there for MANY lead out sets.
Never had any issues with large stunt models and big engines using this equipment.
Just the way I do it, others will their favourite methods, no doubt.