Solder or crimp?
Crikey, Dave, are you trying to restart the war?
My view is that either is OK provided you have a decent crimping tool or can solder and also that strain relief is adequately considered. Soldering is a bit of a lost art these days and soldering terminals can be tricky to get right.
After many years of soldering terminals, I bit the bullet and bought a decent crimper. Professional crimpers used to be quite spendy but not so much these days. The skinny cheap ones still don't do an adequate job IMO mostly because they're just too skinny for the terminals I prefer. I like the non-insulated open barrel-W terminals which are commonly used on our Lotus. I reckon the cheap insulated terminals are the work of the devil.
After some research, I bought a "Teng" brand crimper and it was a revelation - perfect crimps every time. There's likely other brands that are also excellent but that's what I went with.
I don't really like the terminals you show mainly because they look somewhat untidy and would be a hassle to pull through a grommet, for instance. That said, they'll probably work fine. There's also many varieties of straight in-line connector terminals for joining wires.
Am I right in thinking you need those round terminals to accommodate the pigtail for the relay?
It's also possible to get relay plugs disassembled so that you can separately terminate the wires and then click the terminations into the plastic socket.
Anyway, just some food for thought.
Going over a schematic of the relays for the window motors found it more trouble than it’s worth and probably wouldn’t increase the speed any
I reckon the primary advantage of window relays is to take the load off the near un-obtainium switches.