The simulator is limited to 56 drives. The SSD drive size limit is 500MB and the HDD is limited to 9GB. IPartner is trying to build a simulator that will allow testing FlashPools, SnapDiff and copy-to-cloud. I have real NetApp systems, just not all flash.
9.7 does allow for using a different aggregate, so you could set up a SSD aggr and HDD aggr in CVO. I'm not sure of cost, but I was just presenting an alternate option besides Select (if it didn't work for some reason).