I have read the same thing about blix vs. separate bleach and fix. I have had minor problems with the Tetnal 3 bath E-6 kit (excessive density) which has led me to use only the six bath kit. I suspect the Tetnal bleach is more aggressive than most, but residual silver could still be a problem. The use of a fixer before the blix may actually help. The amount of fixer carried over is fairly small, but I suppose it could accelerate the bleach decomposition. Generally, color developing chemicals are used as one-shots, so that shouldn't be a problem.
Originally Posted by Rudeofus