Hi, I'm not sure that it makes any difference, as the total density affects any use that I can see.

I think it's clear that that a sub-visible exposure WILL affect the result of any following exposure, as this IS equivalent to "flashing." I don't think there is any simple way to know that this is going on, so the rule is to be sure no significant light is present during the entire process.

I know that you must have had a reason for asking, if you care to share.