These charts, just FYI, are only helpful as a guideline (except in cases like the NEC where it's a requirement that you follow them). They have to make a lot of assumptions about the environment the cable is in, and tend to be somewhat to extremely conservative for that reason. As an example, I was running 40A through either 14 or 16AWG speaker wire on my first ebike, and that only just got warm because it was in open air, zip-tied to the frame. That same current with the same cable buried in fiberglass wall insulation will fry it in short order.
>So 1050 strands would still be a 0.35 factor like 41 strands?
That isn't referring to strand count, it's referring to CONDUCTOR count. That is to say, the number of wires you have stuffed into a single conduit. They need to be de-rated because, in that case, there are multiple conductors generating heat, but limited surface area/airflow to keep them cool.
On a bike, your only major concerns are vibration resistance and voltage drop. Unless you have something unusual set up where sections of cable are very poorly cooled, your main enemies are fatigue breaking your connections and resistance effectively robbing you of expensive battery capacity. In your specific case, 10AWG, even if an unusually high portion of it is tin, is more than enough for 30A.