I might have missed it, but they don’t seem to talk about the fate and transport of the sulphuric acid that forms when the sulfur dioxide oxidizes. This is important to know.
I find "marine cloud brightening" [0] a lot more interesting. It aims to increase the albedo of Earth by creating more clouds over the oceans e.g. by spraying seawater. Pro: "If implemented, the cooling effect is expected to be felt rapidly and to be reversible on fairly short time scales." , [0] [0] https://en.wikipedia.org/wiki/Marine_cloud_brightening
Sort of; what we're usually doing, in general, is increase the aerosol burden which in turn increases the total number of nuclei available to form clouds. Given that the total liquid water content in a cloud system is fixed (i.e. controlled by factors that are harder for us to influence directly), this leads to a mixture of consequences:
1. The total number of cloud droplets increases 2. The average cloud droplet size decreases
Both (1) and (2) alone tend to increase the albedo of the cloud. They also produce secondary effects, e.g. they can suppress the formation of precipitation or modify microphysical properties that lead to clouds sticking around longer, thereby further increasing their radiative effect (more SW radiation reflected back to space and possibly more LW radiation at lower radiating heights).