You are correct on your last thought, but some clarification is needed for a better understandiing.
1. zD&T uses 1091 driver.
2. Gen-1 uses only token (USB hardware device) licenses.
3. Gen-2 is always software based license. It requires an additional zD&T instance called License Manager (also known as license server).
4. zD&T personal edition can use both: obtain the license from a local USB hardware devce (SHK license) or obtain the license from a remote License Manager machine (LDK license).
5. For zD&T V11.0.x and higher, after installation process, when using software based license you need to activate GEN2 mode executing gen2_init command (https://www.ibm.com/support/knowledgecenter/SSTQBD_11.0.0/com.ibm.zdt.zpdt.license.server.doc/topics/zpdt_ldk_sl_client_cfg.html)
6. Please, learn more about how to configure your zD&T client instance (personal edition) at https://www.ibm.com/support/knowledgecenter/SSTQBD_11.0.0/com.ibm.zsys.rdt.guide.activ.doc/topics/act_cfg_ldk_sl.html.
AdilsonColombo