Depends on the paper...
Originally Posted by f/stopblues
Kentmere bromides and fine art papers did have specific admonitions against washing for more than a hour, unless that's changed. The emulsion would separate from the paper if "over–washed". Washing adequately, without damage could be problematic. Sometimes less than a half hour would result in damage to some discontinued warm tone fine art papers. It happened to me and was well known at Kentmere.Option B:
I've washed Oriental and Ilford papers for as long as 6 hours (accidentally), without issue.
May be your only option unless you know a paper can withstand many hours of backstroking. I would suggest making some attempt at not allowing the paper to dry fully, perhaps keeping it in a high humidity environment until you can wash completely.
Arrange your workflow to include proper washing times in your lab time.