First of all, thank you for the reply! Watching the series in one go has been a very interesting experience. As for the lore explanations, it is finally more clear. So thank you again. There are quite a few things I tend to forget, given how vast Touhou can be at times.
Again, even more lore explanations . I really did not know about the mechanic from SWR and Hisoutensoku, so that is quite new info for me.
We should not forget that besides Scarlet Weather Rhapsody, we have had both Subterranean Animism and UFO teased for almost a decade now (without any sign those plotlines would actually come to be realized). Especially with SA, where we already had like at least an entire minute of solid battle animation. Again, it is the weird order in which the episodes have been created, as well as possibly a lack of general direction that ended up with us having the teasers for 3 arcs, while the creation team is not even sure what are they going to do next.
In some cases, it looks as if they already had something planned, but suddenly changed their mind and did something else. Again, case in point with all the footage for SA. I wonder how things will actually develop in the following years, and in what direction will the series go. Until now, we had Touhou 7, 6, 9, 12.3, 8 and 10 (in this order), with some decent gaps in between. As a bonus, perhaps I should work on a timeline based on all the materials from the show as of yet just to see "the journey of Sanae", from her getting dropped into the setting to the resolution of the MoF incident (use the actual order of the games and put the data together), as depicted in the Manpukujinja-verse.