You say it like we're discussing landing with unseated pax.
The sit down rule is sometimes carried to extreemes. We were waiting for our gate at FRA once, and the F/A confronted a man who got up to use a washroom...They let him go, eventually, and he came back before we even got moving again.
On another experience, one JetBlue crew was good for allowing the pax to use laptops and walk around during 1 hr taxi-out that JFK is known for...
I would say that letting pax unseated is okay if remaining taxi time exceeds 5 minutes, but then again, aircraft don't really have handrails! (or shall we wait for Ryanair?)