client.materialize.tables.TABLE().query(timestamp=timestamp) was ignoring the timestamp value if the table was a reference table, since there is no timestamp parameter on join_query.
Added warnings and workarounds for the cases that the needed endpoints were not yet available, as well. This should resolve the issues Philipp Schlegel was having.
client.materialize.tables.TABLE().query(timestamp=timestamp) was ignoring the timestamp value if the table was a reference table, since there is no timestamp parameter on join_query.