Hi gseaver,
I’m glad you found us even though it may have been a little too late :unsure:
The tutorial includes links to most of the information you would need but I would also read post #2 here which is more about your specific situation and the approach I would take that can help make the best out of a bad situation where you need to exchange a mattress and there are no particularly good quality or value options to exchange for and there are no refunds available.
Unfortunately … outside of the latex … this doesn’t include enough information me to make any meaningful assessment of the mattress (see post #4 here). I also don’t see a Stearns & Foster Brighton listed on their site. At the very least I would need to know the type and thickness of all the layers in the mattress to see how much “unknown quality” materials were in the comfort layers.
A topper can work if a mattress is too firm and doesn’t have any sagging and all you need to do is add some extra softness and pressure relief but it isn’t an effective solution for a mattress that is already too soft or that has any sagging or soft spots (see post #4 here) because you would need to replace the layers that are too soft or have softened or are sagging rather than add to them. I would be happy to make more comments if you can provide more information about the mattress (or perhaps link to it).
Phoenix