Hi! This is now supported in versions 1.0.1 and 0.6.3.
The Planets or surfaces with rain setting accepts a comma-separated list of exact, case-sensitive internal names. The mod checks both planet.name and surface.name. For Space Exploration, add the exact, case-sensitive surface names shown in the game to Dynamic Rain’s setting.
I decided to keep this selection manual rather than automatically enabling rain based on SE tags, since whether rain makes sense on a particular world can be subjective