Do vinyl planks need an expansion joint between rooms?
Definitely check with Trafficmaster for their suggestions, they're really the only ones that know. But, I'd suggest back-beveling your cuts in the middle (or more places) of the full run to avoid any transitions. Back-beveling is just a 1 or 2-degree pie slice cut to the bottom...the top is tight but the bottom has a minor gap.

This way, if there is movement just the top would buckle &amp; can be re-cut or trimmed in place, to fully remove the 1-time buckle permanently.