Spacetime diagrams in (t, ϕ) coordinates for parameters presented in Fig. 5; mean plasma density ρ_mean (left panels) and maximum plasma temperature T_max (right panels), with statistics taken over θ_L3, min < θ < θ_L3, max at fixed radius r = 2M. The black contours indicate log₁₀T_max = 1. The white dashed lines mark linear rotation trends. The upper panels present the prograde a = 0.9 case in the time window 19 500M < t < 19 900M (trend with rotation period 85M); the lower panels present the retrograde a = −0.9 case in the time window 16 900M < t < 17 400M (trends with rotation periods −180M, 70M).