Hi mhswlee,
Congratulations on your new mattress
As you know you certainly made a great quality/value choice and I’m looking forward to your comments and feedback once you’ve received it and have had the chance to sleep on it for a bit.
I don’t see any comments on their site about a solid surface support system but you can see my comments about a solid support surface under a mattress (such as plywood or MDF) in post #10 here. While it would certainly be “supportive” enough … they can be an additional risk factor relative to the formation or mold or mildew … particularly if there are other risk factors involved that could contribute to the formation or mold or mildew in a mattress. Having said that … if there are no other risk factors involved then it should be fine.
Phoenix