Signal to noise ratio, information length, and bit rate

in shortBlockChannelCoding.m.

Now there is a new problem that arises when I set the parameter SNR: 0:1:10;,K=48000;,R=2/3,numR=10000. when the signal-to-noise ratio is greater than 4dB, only the convolutional code has BER, and other codes still break after 4dB, as shown in this simulation diagram.
(1)Is the simulation frame rate not large enough, or is the information length K not long enough?
(2)Another question is whether the length of information K has an impact on BER?
(3)When my message length K=480000, what is the bit rate set to avoid errors.

Besides, I have another question. I want to compare these four encodings under normal circumstances, such as a signal-to-noise ratio of 10-20dB, information length of around 100000, and a bit rate of 1/2 or 1/3. In this case, compare the BER of the four encodings.
(1) Can I directly modify the encoding length, bit rate, and signal-to-noise ratio to see BER in the shortBlockChannelCoding. m scene?

(2)If it’s not possible, how should I modify this scene?