In January 1995, a Japanese newspaper revealed that a sarin compound had been found in an Aum Shinrikyo facility in Kamikuishiki. The cult leadership panicked and ordered the destruction of their stockpile of chemical weapons and precursors, because they thought they were going to be raided by the police. This included 20 liters of sarin of relatively high purity. Then, in March, when they decided to launch the subway attacks, they had only a small amount of precursors on hand that had been hidden instead of being destroyed, and were only able to produce 6-7 liters of sarin of about 30% purity. So, with a small PoD, they would have had a lot more sarin than they did IOTL. And their dispersal mechanism was poking holes in a bag of sarin liquid with an umbrella and then running - they could have developed a much more effective method.
Historically, only 13 people died in the Tokyo subway attack. It seems frighteningly plausible that, if the cult had been a little more skilled or a little luckier, they could have killed a whole lot more. What if they did? How bad could it get, and what would be the consequences?