In Horizon you can choose to have single-session VDI (e.g. Win10 OS) or multi-session VDI (RDSH). Assuming they are using single-session VDI, they create a base image including the necessary software and that image is cloned to a VDI for each user. So there should be no problems with your software.
The Horizon Datastore is probably the vSphere datastore where the VDIs are stored. There's no such thing as a Horizon Datastore.