You can specify custom weather files through the weather_station_epw_filepath argument in options_lookup.
Example:
weather_station_epw_filepath=../../../weather/G0100010.epw
https://buildstockbatch.readthedocs.i...
That answers the question of how to use TMYx. Whether (weather?) you should, I'm not sure. The IBPSA article mentions "Currently, there are more than 13,550 TMYx locations supplied. This is the same dataset and methodology used in the creation of TMY3 files, although some stations may have been taken offline, and new ones added."
If the same weather stations were used for TMYx as for TMY3, just with more recent data, you can probably assign appropriate TMYx EPWs in options_lookup and go from there.
Maybe this source can provide insight.
https://www.ibpsa.us/ask-a-modeler/as...