Recent studies show that plants literally respond to anesthetics in a way that is indicative of them preventing “pain” https://pmc.ncbi.nlm.nih.gov/articles/PMC6215046. Similarly they also recently showed that plants can be desensitized to negative stimuli, here they drop a plant that physically reacts to stimulus and record the expressed atp. By a thousand or so drops the plant is no longer reactive to the minor stimulus, but still reactive to other similarly impactful stimuli. This could suggest that the plant is able to remember the consequences of the dropping and is no longer inciting a stress response, whereas new/known bad stimuli are still demanding of a defensive stress response.
I just don’t think plant life is as clear cut as people make it out to be. There are more studies showing things like related bean stalks grabbing the same poles but unrelated stalks avoiding sharing a pole together, or trees using root systems to provide nutrients to neighboring trees that would otherwise starve out.
Unless something changed from the novels, no. The goddess’s spring is just only active in the way we see for that one night, which is why it was mundane earlier in the episode.