This article is focused on providing additional value, more details on deciduous bonsai care and reminding us of important details as provided in Bjorn Bjorholm's very instructional video.
This is by far the best tutorial you could find about repotting bonsai trees, "covering a lot of ground" on a range of use cases you might have to tackle when repotting.
One to watch. And if you think you know a thing or two on the subject, watch it still and let me know if it was worth your time.
Trees grow from extracting the carbon they find in the 0.04% CO² in our air. Not from the ground, not from the water they find in there. They break apart the carbon from the air and release the oxygen for us to breathe. The carbon is converted to glucose, then to cellulose and finally into wood itself.
That is why trees thrive in pots: they only need ground to anchor their roots and extract additional building blocks. This is why growing trees is such a slow process.
I am not going to bore you with my personal views on bonsai pottery. So I keep it brief and point you to the references that are meaningful. This is by far the most insightful YouTube I watched about quality of clay and glaze to date:
https://youtu.be/KgsoSudK14Q?si=e_wFv5O3SuOzxpIQ
Are you contemplating to baking boinsai pots yourself? NaoTokutake, a reknowned American potter recommends digitalfire.com and you will figure it out.