Very cool Andrzej!
Despite the fact that natsume are for matcha/Japanese Tea Ceremony, I have been breaking the rules lately. I purchased several vintage Makie Natsume from Japan but they sat idle. I deceided, why not use them for sencha just like for matcha. I put the amount of one session of sencha in the natsume which then sits on the tea table as I prepare water, pot, cups, etc.
When the water is the right temp, I simply dump directly from the natsume into the preheated kyusu.
The natsume are happy to be used and I am happy to see them used every day!
Point is, your "natsume?" would also be great for daily sencha!