Hi,
what do you think about adding known mappings directly to the project as iobroker does?
See https://github.com/Apollon77/ioBroker.tuya/blob/master/lib/schema.json

They use the product id to identify the dp mappings. So you don't need any connection to the cloud if you know your localkey and product id.

I used it in my project as well where I use a combination of tinytuya and localtuya (because of asyncio) code:
https://github.com/fhempy/fhempy/tree/master/FHEM/bindings/python/fhempy/lib/tuya

Would be great to make one mapping list in tinytuya where everybody could contribute.