Dimitar, sorry for my English.
Now I understand that you develop Orwo slides in reveals procces - b&w - Rodina diluted 1+ 100 for 2 hours.
Chromogen developer - RA-4 dilute 1 +10 and developed it for 10 minutes at room temperature.
The C 41 diluted 1 +10 and development time 2 hours.
Processing films emerged at high dilution and in particular, that the b&w (for the reversible color film) do not think is a good idea.
I read much in a magazine an article translated from Russian showing that most importance in photochemical processing has the alkaline substance.
Not developping substance as everyone would expect.
I look at the black from perforation because there does not receive exposure film and the process will result in reversible color black.
I found the post with C 41 developed at room temperature. Development time was 16 to 20 min. with undiluted developer.
The pictures look decent.