locked #FST4 (and other LDPC modes) #FST4

Andy Talbot

Why do the four-tones LDPC modes FT4 and FST4 (but not FST4W) have
the source scrambled before adding the CRC and parity, whereas
the other modes, FT8 and MSK144 don't?

I can't see any obvious reason for scrambling the compressed message data
of just the four-tone modes over any of the others.