Maybe not. We crimp various kinds of pins and sockets every day in the aviation community. It's more a matter of having a compatible crimping tool than anything else. I have worked with crimpers that will crimp up to a 2 gage wire without damaging the terminal being crimped to it.
When I built my airplane, I too used a good crimping tool and solder to make my connections. But those connectors are made from either plated steel, or plated copper. Model brushless motor connectors are not made like this, but rather they are made of a bronze alloy that has something in it to make the bullet "fingers" have some spring back, so that they can collapse while inserting, but spring back enough to hold tight in the female connector. You CANNOT crimp them!
I use to make battery cables for diesel tractors using very large cable. Those cable ends were made of soft pure copper. I had a 3 foot long crimping tool, and it would squeeze those ends on perfectly with no need for solder.
What about maybe tapping the solder hole and putting in a short #4 -#6 grub screw then solder?
Mic, after I started rewinding and pulling twice the amps as I use to, I started melting connector solder constantly. We tried all sorts of mechanical connections including a 1" long piece of copper, bored to take the motor lead and esc wire overlapping the full 1 inch. And that copper had 4 grub screws locked down solid, and soldered the whole shebang with 60/40. IT STILL MELTED on the first run! Yes, I was using to big of a prop, but I was doing that on purpose to try and fix this solder problem.
Doug Smock had given me some hi temp solder earlier, but I could not make a decent connection with it and gave up on using it. I bought two different soldering guns To try and use the stuff, but neither would get hot enough.
After the failed monster connector attempt, I did some research on how to use the hiTemp and got to where I could make a good solder joint with it. You have to use a torch! This solved the melting connector solder problem completely.
Using too low heat capacity of a soldering device is worse than having a high capacity tool.
The idea is to get in, make the solder joint, and get out. Holding a low capacity tool to the joint for a long period of time is what causes most joint failures.
Oh, and acid flux has no place in electrical wire work. Rosin flux only.
Only my opinion, and I have been doing wiring in one form or another over 40 years .. computers to automotive to heavy diesel... industrial refrigeration to transport refrigeration,, monster 4/0 wire to battery cables to tiny 32 gauge...
Take it with a grain of sand ..