Please keep in mind that the blix solution, no matter what the dilution, must go to completion. The time and temperature for developer is however critical for its proper performance. Blix is entirely separate and must convert silver to the halide and then remove (clear) it leaving only the dye components that were formed during the developing process.
Blix is not generally thought of as preferable to separate bleach and fixer, but it does work most of the time. If you use a stop bath following the developer (2% acetic acid with some bisulite) then the blix can be done in room light allowing you to easily see that it has worked to completion. Bleach and fix can be re-done if required. The image consist of silver and dyes, and is formed in the developer step and development ceases in the stop bath. Bleach converts silver in the exposed parts of the image back to halide and the fix removes all the halide leaving only the dye image. The concentration of blix and its temperature and timing is important only to take the process to its completion without being long enough to degrade the dyes that remain in the image
Hope this explanation helps. Experimenting with a few pieces of test film will get you going on the right track.