Perovskites are exciting (or were exciting) because they have a high theoretical efficiency, are relatively simple to prepare, and the "worst" component in them is lead (an incredibly abundant material). The big problem with them is that they are famously horrifically unstable in ambient conditions.

Roll-to-roll processing means that you can fabricate them in mass scale. Ambient means that they claim to have solved issues like working in glovebox conditions.

Even if the price of solar panels has come down below labor, the fact that they are produced from rare earth minerals goes (in my opinion) underreported.

Consider the relationship between perovskites and multi-junction solar cells similar to the comparison between sodium and lithium ion batteries. Lithium will always have a higher capacity, but sodium is so abundant that for many applications it just doesn't matter anymore.

They produce 60-80 milligram of calcium carbonate 'per fiber', per 30 hours. I'm interested to know how they keep the bacteria alive over time, through the concrete curing process (high temperatures, high level of carbon dioxide, making any liquids in the vicinity highly acidic), and how the bacteria remain viable over time. Concrete we consider to last over decades, or a century?

From a chemist/material scientist perspective: Whether the results of the Riff trial may ever have a p value suitable for nature/science, likely not. When it comes to the human body and our biology, a mass trial like this may even be more useful than traditional studies, where pre-existing biases in data collection may weed out the most useful 'Riff'. Better than that, the information collected by mold_time is regularly released and discussed, in the open, on twitter/x [2].

[0] https://www.nature.com/articles/nature25476

[1] https://www.youtube.com/watch?v=CglNRNrMFGM

[2] https://twitter.com/mold_time