Not exactly.
Originally, Palimpsest was going to get a novel-length expansion, but that's problematic—it's really hard to write.
Meanwhile the other trouser-leg-of-time from the story—the wormholes-for-space-colonization leg—exists as a space opera but needs a redraft next year. And I have plans for another story in that setting.
(It's a Culture-scale universe that got steamrollered by the two other huge multi-book series I was working on. Now Laundry's nearly done, it may emerge.)