you may have seen that R CrB has started a steep descent of brightness. It looks like the start of the last decline in 2019 which went down to mag 8.5. Before, we have seen minima even below 14. As this is a famous star quite some people observe it visually and photometrically, some also take spectra.
In the textbook from Gray and Corbally (page 323, Chapter 8.4) there is an interesting comparison of spectra from bright and very faint phases of R CrB where the spectra changed from a typical G-type Carbon star to a more nebula like spectrum.
Maybe an interesting target to observe if it really goes down in brightness (dust clouds formation) significantly.