workaround by temp table and max_allowed_packet / 2 sized packets 
kinda ugly
If you use the C API to access MySQL and if you use the prepared statement protocol, then you can send a BLOB in multiple pieces. The packet size limit applies to each piece you send, but the BLOB as a whole can be larger.
This is done with the API function mysql_stmt_send_long_data() which is documented in the MySQL manual here. There is even an example how to use that function.
You didn't say which connector you use to connect to MySQL. But if your connector is based on libmysqlclient (aka the C connector) then there is a certain chance that it exports this function as well.
I'm closing this for now as not a bug. If you disagree or/and want to convert it to a feature request, please feel free to comment to-reopen.