Interesting discussion. Although is is intuitive to assume a lug connection you can swing across a pit of alligators on is better than one that is (just enough) electrical connection. My understanding is that stranded wire has higher ampacity than a solid copper crossection, which is what you are doing when you crimp the hell out of a stranded wire into a solid copper wad at both ends of a butted connection. So maybe the goal is to size your butt connector to allow for some interlacing of the strands inside the butt and then just crimp over the area of this interlacing. Also, to back up to ensure more "mental insurance" consider the need to be concerned at all about this issue and look up the time to heat up under actual intended load. Here is a website/calculator that will tell you how long it will take to max the insulation rating for your wire. If you are using 00 wire and it says 350A constant load capacity, then why does Tesla use this size wire and hook it up to a motor that can see 1300-1500A for short durations. Using the website below you can play with figures that you get from measuring the resistance of your butt connection vs a un-butted length of wire.
Short-Time Current Rating of Conductor - Time Calculation
Webpage calculator to calculate the Short-Time Current Rating of Conductor
www.nepsi.com
