Is there a way to customise a Kafka Deserializer in Kafka Ingress of Flink stateful function?

Question

In my project, I am going to use flink statefun kafka ingress for consuming avro-serialized records from kafka, but it seems there is no config parameter for users to specify the deserilizer for deserializing the kafka record's key, in the source code RoutableKafkaIngressDeserializer, I also noticed the key is directly converted to String from bytearray.

I tried to specify the deserializer by kafka consumer property key.deserializer, but it is not a feasible solution according to flink kafka additional properties

I found kafka deserializer can be specified through datastream API Kafka deserializer, unfortunatelly, this configuration seems not available in flink statefun kafka ingress for now.