I have an RNB and have never noticed gaps like that. However, I just looked and found that I could create that gap if I push the back burner against the back and move the front all the way forward so there is some play.... maybe a quarter inch w each? Just pull your back grate more forward, you can't really notice a gap all the way back there and hopefully it will close the gap you are seeing.

I am also getting a considerable gap side to side

Maybe you could contact Bluestar ranges and send them pictures and comment on the gap issue.

Any updates on this? What did BS say? Do other owners have similar gaps?

Bluestar customer service said the large gaps were normal. I am going to check out another unit in a showroom to measure the gaps to compare. i believe this is only an issue on the 30” models (with the center spacer grates).

@Graeme Smith Thanks for posting back. For the side to side gaps, I'd agree, but it looks like you have front to back gaps, too.

Resurrecting an old thread.

I have a Bluestar RNB. I had a RCS at a prior location. I love the range. Simple and powerful. Nothing really to break. On the old RCS I had an issue with oven control being sloppy. This looks to be resolved in my new model. My complaint on the new model is there are large gaps between the cast iron cook grates up to 7/16 of an inch. Bluestar says that is within tolerances but I feel for $6K they should do a better job.