The default message size used in the e2 code for allocation of messages is defined by -

#define RECEIVE_SCTP_BUFFER_SIZE (256 * 1024)
#define RECEIVE_XAPP_BUFFER_SIZE RECEIVE_SCTP_BUFFER_SIZE 

This is a buffer size of 256K. Which is a very high buffer size since most of the E2AP messages (and consequently RMR messages) will be way smaller than this. A size of 4K should be sufficient.

Since there may potentially be some allocations that would happen in some functions, using a smaller message size may help with performance a little bit. A default size of 4K should be sufficient?