Median reaction time for all block start events (100 m, 200 m, 100/110 m hurdles) for World Championship meets:
0.155 men iaaf-world-championships-london-2017-7093740
0.151 men 15th-iaaf-world-championships-7078726
0.161 men 14th-iaaf-world-championships-7003368
0.155 men 8th-iaaf-world-championships-6947294
0.156 men iaaf-world-athletics-championships-doha-2019-7125365
0.157 men 9th-iaaf-world-championships-in-athletics-6930156
0.160 men 11th-iaaf-world-championships-in-athletics-6903480
0.144 men 7th-iaaf-world-championships-in-athletics-6939522
0.152 men 12th-iaaf-world-championships-in-athletics-6998524
0.152 men 10th-iaaf-world-championships-in-athletics-6937596
0.170 men 13th-iaaf-world-championships-in-athletics-7003367
0.133 men oregon22
0.160 women iaaf-world-championships-london-2017-7093740
0.162 women 15th-iaaf-world-championships-7078726
0.171 women 14th-iaaf-world-championships-7003368
0.157 women 8th-iaaf-world-championships-6947294
0.155 women iaaf-world-athletics-championships-doha-2019-7125365
0.162 women 9th-iaaf-world-championships-in-athletics-6930156
0.158 women 11th-iaaf-world-championships-in-athletics-6903480
0.149 women 7th-iaaf-world-championships-in-athletics-6939522
0.158 women 12th-iaaf-world-championships-in-athletics-6998524
0.158 women 10th-iaaf-world-championships-in-athletics-6937596
0.171 women 13th-iaaf-world-championships-in-athletics-7003367
0.140 women oregon22
Oregon does seem to be fastest and it's not just Allen.