My Acurite shows 5 minute data buckets, so this might be a little harder than I'd like
I haven't been following along. IIRC the Access posts to an https URL. Is it possible to intercept the Access traffic by hijacking DNS? Does it check the SSL/TLS certificate?
One thing I was able to see today with MyAcurite that people with consoles reported is that the strike count displayed by Acurite consoles and MyAcurite goes up when either the field that seems to be the strike count increments or the field that seems to be the strike distance changes, and there also seems to be a correlation with the USSB1 (unknown strike status bit) also toggles.
If the 6045M requires keeping state to infer the events, rtl_433 will only ever just output raw data. A consumer of the data (ike Weewx) would have to check the last message and look at the most recent message to figure out what the new state is.