Well... an update from the honkie froggie! Looks like KlowdTV has a dedicated box of their own, with a 14-day cloud-based buffer of shows that can be re-watched. As long as you don't want to save your shows for longer than that, time-shifting looks possible with any channel available on KlowdTV.

I still have to research more into this. By going with a dedicated KlowdTV box, you sidestep the Roku entirely. Might add a further update later, but this is encouraging.