I am not absolutely sure, but it seems that, serial "bufsize" setting does not do what it is meant to.
Default value is 2048, but when 2048 bytes are sent, only 1024 bytes arrive to another device. When sending the [bufsize 2048] message, serial object lags and I have to force quit.
Have you had this experience before or tested it with bigger values ?
I could iter my big list before sending it to my led matrix, but then some aliasing effect happen.