Even without ABYC weighing in Practical Sailor did a test of these things compared to the standard crimps overlaid with heat shrink tubing, adhesive lined. They concluded the joint was inconsistent connector to connector and thus not reliable.
I suspect ANY hint of oxidation of the wire will interfere with a proper solder connection. I've seen that to many times to play with these things. Unless you can absolutely guarantee that the wire itself, ALL STRANDS, is absolutely shiny, bright , clean there is a chance, a good chance that the joint will be questionable.
Like someone else pointed out that they carry crimpers, I do too, and I carry a heat gun but unless I have a power source it is of little use. Crimpers don't care and a flame, don't like that either, will shrink the heat shrink without burning the tubing with some care. I'll guess that the flame will burn the heat shrink before a reliable solder joint is achieved.
My butane solder iron will shrink the tubing after the crimp with its shroud.
To me there are too many negatives to take a chance on a squiffy connection when I know I can do better more reliably.