WordPress Multisite and Domain Mapping
WordPress Multisite can be very useful in some cases, however it is not meant as a replacement to be used for individual sites, so unless the sites you install within a multisite network are all related in some way, we would not suggest using it.
Due to how our licensing works with support/updates we do not allow hosting client sites in a multisite network. this is mainly because the use of domain mapping or using an alias domain name instead of the site address that is assigned to the sub-site, as these wouldn't properly license.
The only exception is If you are hosting client sites and are using developer keys that are assigned specifically to your account (and not license keys from clients who have their own copy of OptimizePress) then you can license a subdomain of your network for a client (but still can not use domain mapping).
Just know that our licensing will not work with aliases or domain mapping. You can only use the subdomain (or folder). This is a flaw with how the multi-site works. When a license key is used it can only attach to the "site url" from the "sites" section and not an alias. . Using domain mapping and aliases will lead to issues on any site that you need to use domain mapping on because the alias domain wouldn't be able to be licensed. This is why we do not recommend using multi-site for anything other than your own sites (with subdomain or subfolder).
If you have further questions regarding the use of domain mapping, using multisite with OptimizePress, or have any other questions, please let us know and our team will be happy to discuss any questions you have.