As a general rule my belief is that overall stain, which functions like b+f, should be avoided. Very high levels of non-image stain may have some benficial results in limited cases but the benefitws with most films and formats are outweighed by the negatives.
Briefly, high levels of general stain result in:
1. longer exposure times
2. lower contrast
3. some grain masksing
On the whole the advantage of grain masking may outweigh the longer exposure times and lower contrast for medium and high speed 35mm films, and for high speed 120 film.
For sheet film of 4X5 and larger size there is rarely a need for grain masking since these films already provide smooth grain at normal enlargement sizes. Therefore, printing negatives 4X5 and larger, even with silver gelatin printing, the longer exposure times and loss of contrast are more signifiant than any grain masking that make result.
For alternative printing where a fairly high Contrast Index is needed, and exposures with UV light are fairly long (even with film with low shadow density), the loss of contrast and longer exposure times are generally unacceptable.
For alternative procesess