C41 b&w can be done in b&w chemistry. For instance, Ilford XP super can be souped in Diafine, fixed and washed, so long it is rated at EI 250.
This is because Ilford XP Super does not have the orange mask like Kodak TCN400, or even the Kodak Portra BW (which was a joke and discontinued). Scanning wise no problem, printing these trying to print negs with orange mask/base in darkroom gives u very flat print.