The ratio between the combustion engine and the battery is currently 50/50, when it's not 50 and 0 because the battery is empty. That has led to a number of inconveniences. Among them, cars that accelerate crazily but eventually lose speed along the straights when they run out of battery.
In 2027 the ratio should be 60/40 with a slightly more powerful combustion engine or less battery and the plans for 2031 are to go back to a v8 engine with green fuel and probably a KERS like in the early 10s.
So BYD will probably never be in F1. Maybe Formula E?