The COVID-19 pandemic has led to the growth of hybrid and online learning environments and the trend of introducing more technology into the classroom. One such change could be the use of smart synchronous hybrid learning environments (SSHLEs), which are settings with both onsite and online students concurrently, where technology plays a key role in sensing, analyzing, and reacting throughout the teaching and learning process. These changing environments and the incorporation of new technologies can place a greater workload on participants and reduce teacher agency. In light of this, this paper aimed to analyze the workload and teacher agency across various SSHLEs. The NASA-TLX model was used to measure the workload in several scenarios. Questionnaires and interviews were used to measure teacher agency. The results obtained indicated that the workload of the teacher tended to be high (between 60 and 70 points out of 100 for the NASA-TLX workload), especially when they lacked experience in synchronous hybrid learning environments, and the workload of the students tended to have average values (between 50 and 60) in the SSHLEs analyzed. Meanwhile, the teacher agency did not appear to be altered but showed potential for improvement.