Examples of the background-included, point-source-corrected smoothed X-ray images of the high-z samples. Left: 0152-1358 – very structured cluster at z = 0.83 with P3/P0 = (5.76 ± 0.95) × 10^-5 and w = (6.64    ±    0.57)    ×    10^-2. This 400SD cluster has the highest P3/P0 value and is marked by a circle in Figs. 5−7. Right: SPT-CLJ0509-5342 – rather relaxed SPT cluster at z = 0.46 with a non-significant detection in P3/P0 and w = (3.13    ±    1.33)    ×    10^-3. The circle indicates r₅₀₀.