In the class org.apache.avro.hadoop.io.AvroSerializer, we see that the Avro block size is configured with a hard-coded value and there is a request to benchmark different buffer sizes.
However, there is no need to benchmark, this setting is superfluous and is ignored with the current implementation.
org.apache.avro.io.EncoderFactory.binaryEncoder ignores this setting. This setting is only relevant for calls to org.apache.avro.io.EncoderFactory.blockingBinaryEncoder
which considers the configured "Block Size" for doing binary encoding of blocked Array types as laid out in the specs. It can simply be removed.