.t6 file system is good, but there is thousands of stock tickers in the markets.
If someone try to save stock history price datas to .t6 files, maybe thousands of files needed in one folder.
This cause extra efforts to manage data.
To resolve this problem, I kindly suggest HDF5 database support to save historical price data.
Using this database format, we can write all stocks historical data to a one file.

And also there is not enough room to save historical datas to a only one folder,
I recommand that zorro can recognize sub-directories of history folder.