While it remained, northern hemisphere temperatures lowered by ~0.5°C.
USGS report: https://pubs.usgs.gov/pinatubo/self/
Since the stratosphere is far above the rain cycle, it's very hard to imagine a mechanism whereby this could produce acid rain, and even if it did, acid rain is a much smaller problem than global warming.
In fact it used to be a common occurence during the heavy industrial pollution in the 20th century. So much that after the pollution stopped, farmers had to start applying sulphur to their fields as nutrients for some crops (I learned about this after unsuccessfully trying to grow tomatoes in alkaline soil).
I remember watching news reports about acid rain in the 90s and being terrified that any ominous rain cloud might be full of acid rain which would melt away my town and family.
> acid rain is a much smaller problem than global warming
Possibly, but acid rain can devastate marine ecosystems and cause issues with soil quality, so I'm not convinced that we can just hand-wave it away.
I can foresee greedy capitalists rubbing their hands together over being paid to seed SO2 into the stratosphere and then being paid to clean it up too. There's probably a lot of money to be made selling clean air if we can pollute the atmosphere enough to cause health problems for people.
Humanity has a track record of making assumptions about complex systems and treating them like a simple engine.