Is Subwoofer Elevation a Viable Option?

So, why do we even want the bass to be "reinforced"?

If the low frequencies aren't reinforced in a uniform way, that might be of some benefit, but I very much doubt that's the case. Even if it does, why not just increase the loudness instead adding room boom?

Maybe if we have less reinforcing we can save some dollars on bass traps.

The reason to use multiple subs isn't reinforcement so much as it is to break up standing waves- that 'room boom' you mentioned, or it can manifest as a lack of bass at the listening position while there is good bass elsewhere in the room.

Furniture is always included as a way of mitigating bass frequencies and serves the same purpose as a bass trap. 

It would have to be specially designed to actually be a bass trap. Its much better at absorbing higher frequencies. Wherever you got that idea about furniture being an effective bass trap is erroneous and might be part of why this thread exists.

 Since subs produce low frequency audio which is Omni directional there is no need to elevate.  In bottom firing subs elevation would be counter productive. 

I have run multiple subs for a number of years in different rooms. Good news,  furniture has minimal impact on sub. That said, elevating subs does change how they interact in the room so it is worth experimenting with. You'll lose some reinforcement from the floor but you may like how the sound changes. Like all things in the hobby, let your ears decide what you like best.

Elevated on of my REL S/510's by stacking one on top of the other and it was a game-changer. Ended all my moving around silliness.

@artemus_5 REL's are made to be stacked (if desired). That's why they come with those brackets and screws. I attended REL's subwoofer seminar at Upscale audio and specifically asked REL rep about this.