Bose soundbar 700 universal remote and Roku 3

I expect your Bose remote controls via infrared (IR) signals.  The Roku 3 came with a remote that controlled via radio frequencies (RF) that allowed the Roku to be placed out of sight.  But they also have an infrared (IR) detector that allows it to be controlled by the same set of IR commands used by all non-Streaming Stick Roku devices.  To be controlled by IR, the Roku needs to be located in view where the direct line-of-sight IR signal can find it.

Bose remote code reference pdf document lists Roku as 02457, both under TV and GAMES.  This makes me a little suspicious that this is the code to control Roku TVs (those that have Roku capabilities built in) which respond to a different set of IR commands than the separate Roku devices do.  But it can't hurt to at least try it.