Hi ineedmoresleep,
That’s good news :).
I would sleep on any new configuration for a few days at least so that you have a chance to identify any clear patterns in your sleeping experience because your experience for just a single night or two can often be an anomaly or the result of your body adjusting to the change itself.
As you mentioned … I would also keep in mind that 3 lb memory foam may soften or break down faster than higher density memory foam so your initial experience may be different than your experience after the topper has broken in or after a few months of sleeping on it.
I believe that SleepEZ will also exchange a latex layer for a 5 lb memory foam layer (although I would check with them to make sure) so this may also be worth considering as well (although 5 lb memory foam will probably feel firmer than the 3 lb memory foam you are currently trying).
Sleep well!
Phoenix