I watched your video. Well done! A couple of things from a dude who has driven his same 2014 S85 since new in May 2014.
The serial numbers of the first 85kWh battery packs ended with the letter A. If you look in the right front wheel well with the tires turned, you should be able to see the part number. If it ends with an A, then that is more than likely the original battery. "A" series packs were limited to 90kWh Supercharging speeds. With a 2012 model, it is quite possible that you have one of the original packs. Those packs were not subject to the issues (reduced charging speeds and the temporary reduction in battery capacity) that later models experienced.
For elevation gains/losses I would suggest a more strenuous drive than a light-to-moderate drive from sea level to sea level that crosses the hills on the Riverside Freeway and then descends into the Coachella Valley that is below sea level by and large. (I happen to know Cook Street and the urban-style [72kW] superchargers in that outdoor shopping center on Bob Hope Drive.) A drive up the Grapevine and down to the Superchargers on either side of Interstate 5 at the Laval Road exit might provide better insight into the losses on ascent versus the regeneration on the descent. The SC at the outlet mall on the east side of I-5 can charge up to 250kW (Models 3 and Y). They have the skinny cables and the stalls usually do not share the power feed. The SC on the west side of I-5 are the older Version 2 SC with the thicker cables and a maximum output of 150kW. That style shares power with like-numbered stalls, so 1A shares with 1B and 8A shares with 8B and so on. This sharing means that if I plug in and start receiving 105kW, and you plug in 10 seconds later at the paired stall, I will immediately drop to 72kW, and you will receive a maximum of 72kW. I get barely 100kW on my '14S 85 during hot weather on either style for a short time if the battery level is < 15%.
I might also add to illustrate that the battery charges faster at lower states of charge. You could plug in with ~40% state of charge to see the rate and again with ~15% state of charge to compare the speeds. The differences won't be as noticeable if you have the 90kWh limitation with an A series battery, but will still be revealing.
Again, nice work!