Congrats on your RBTA - If it actually stays where you originally put it consider yourself very fortunate. I added mine early before much else was in my tank (thankfully) as it spent the next 30 days covering every inch (vertically and horizontally) of the the tank.
I got lucky in that it settled front row center in the tank, in a high flow, medium high light area that allowed me to arrange everything else around the RBTA.
Even then, I didn't fully allow for the size changes when it gets "happy" and fully inflates. It creeps up on an SPS shelf, so I had to adjust a MP20 to keep a strong current over the edge of the ridge to "persuade" it from going further. It's been a couple of months and it seems happy with the arrangement, but you never know when it might decide it's time for a road trip.
I think the bottom line is, when you an a Nem to a tank you no longer have control - it does