With this split development you run the risk of crossover with color negative films.
Part a is still subject to oxidation and will not keep much longer than a few months unused.
In any case, the developer is missing potassium iodide which moderates the interimage and DIR effects and therefore will not give proper control of the curves, edge effects and color correction.
For cross processing, it will hardly make any difference.
There are a lot of substitute color formulas out there, but few people have fully checked out the developer with a variety of films and I have never seen anyone check them out for image structure.