First, I'm not sure you have rights to give to your user design-time license, because user wasn't bought developer tools (VS, VFp, etc.).

Second, even you give to your user design-time license, in VFP there are no way to use it at run-time. Fox example, in VB you can first load license information in special collection (Licenses collection). Then, when you call Add method of Controls collection it's automatically checks if appropriate license exists in Licenses collection. In VFP, there are no Licenses collection (or something like Licenses collection) and this mechanism is not supported.