I can say after working CW about 95% of the time for almost 60 years, (year short of that & 4 years of that in the military service as an op) I have discovered that having a call sign that ends in a dit or one that has like a B and 6 after it is difficult for most CW ops to copy in contests. Sorry not the fist, those CQs are sent out with an automatic keyer. One of my ex calls was WB6GBR. Terrible in contests. If someone answers my CQ and accidently missed a letter or number that is fine I will slow down for them. If someone comes back abusing my call I don't respond. This is my hobby, I love to copy CW, somehow I don't see humor in abusing anyones call. JMHO because I am old and grumpy.