- "The burning vinyl chloride produces hydrogen chloride (which becomes hydrochloric acid when in solution with water). Tens of thousands of pounds of it was present."
A single Space Shuttle / SLS launch releases far more than that [0]. The solid-fuel boosters are 70% ammonium perchlorate; the primary form the chlorine ends up as is HCl. No one ever gave a shit.
Really, the HCl component is the least concerning part of this disaster. This isn't 1970's-era acid rain, from the coal industry releasing sulfuric acid on a million-ton scale.
[0] e.g. Table I, https://apps.dtic.mil/sti/pdfs/ADA289852.pdf ("Stratospheric Ozone Reactive Chemicals Generated by Space Launches Worldwide")