The topic of saprobic behavior among lichens intrigues me often despite having to note to people that epiphytic lichens do not "harm" trees. There is a new great paper (albeit not yet peer reviewed) that I read recently examining how much lichen genomes have retained their ability to produce enzymes for carbohydrate decomposition and what role that may play in either accessing nutrients from the photobiont or for substrate attachment. This is a worthwhile consideration: how do lichens not do what fungi especially ascomycetes know best to do and not decompose the photobiont yet utilize its nutrients? Here is the link to the paper:

Large differences in carbohydrate degradation and transport potential in the genomes of lichen fungal symbionts | bioRxiv

Bruce I could not agree with you more about your frustrations with iNaturalist and sadly I see a trend among younger people to bemoan traditional keying skills because of their reliance on iNat's unreliable ID suggestions. While it can be useful at times, some of the users have legitimate expertise like Fred Rhodes, nonetheless as a tool it requires much vetting particular with lichens.