Hi rob2121,
Some people sleep warm on any kind of memory foam (especially if it’s a softer and thicker layer) and your sheets and mattress protector may also be contributing to your sleeping temperature as well. There is more about the factors that can affect sleeping temperature in post #2 here.
I would probably give any new mattress a minimum of about 2 weeks so it has a chance to break in and you have a chance to adjust to a new sleeping surface and then if you still want to make changes to the mattress it would be a good idea to talk with them about the type of changes and the options you have that may bring you closer to the “feel” you are looking for. Your mattress also has a thicker memory foam layer which may also be part of the reason for the difference you feel in edge support. My previous reply here listed the materials in the weightless mattresses and as you can see your mattress has much higher quality materials but the designs and layers are also quite different so it’s not surprising that it feels different for you.
Hopefully your experience will change over the next few weeks as the mattress breaks in but if not and you need to make changes I’ll be interested in what you decide to change after talking with them and of course your feedback after you’ve slept on it as well.
Phoenix