physically it's a new Visa issued previous Visa are automatically canceled. But this doesn't say anything about the success in applying especially in Japan.
I once try to apply for a Chinese visa in Japan and they were flat refused and were very rude and these were Japanese people...
hotels have 24 hours to file your TM 30 so one day may not be enough....
Also for the initial Visa (or first extension) don't we need to see the rental contract for the place you registering it? Sorry if this isn't applicable.
transferring at least in Bangkok it does not require an appointment and it's possibly done without a wait, i think. I think that they can even do it at the same time when you do the renewal, that's what i did during covid. Just ask to be sure.