Due to the absence of peritectic transformation, β-solidifying γ-TiAl alloys exhibit minimal compositional segregation, thereby demonstrating outstanding thermomechanical processing capabilities and high-temperature performance. Manganese, serving as a cost-effective and potent stabilizer of the β-phase, plays a pivotal role in the development of economically viable and easily deformable β-solidifying γ-TiAl alloys. In this investigation, we focused on a low-cost and easily deformable Ti-44Al-3Mn-0.4Mo-0.4W-0.1B-0.1C alloy (at.%), which was rolled into 12 mm diameter bars via vacuum induction melting and conventional hot rolling techniques. Various characterization methods, including electron probe microanalysis (EPMA), transmission electron microscopy (TEM), and electron backscatter diffraction (EBSD), were employed to scrutinize the effects of high-temperature treatments at 1270 °C, 1220 °C, and 1170 °C on the microstructure and mechanical properties of the alloy bars. The findings reveal that post-heat treatment, the microstructure of the alloy comprises γ, α₂, and β_o phases. Decreasing the high-temperature treatment temperature under identical aging conditions significantly reduces the α₂/γ lamellar content within the alloy. Moreover, both the size of the lamellar colonies and the spacing between lamellae exhibit pronounced reductions as the treatment temperature decreases. The tensile performance tests demonstrate that as the high-temperature treatment temperature decreases, both the room temperature and 800 °C tensile strength of the three microstructures decline. At room temperature, the elongation of the heat-treated microstructures shows a trend of first increasing and then decreasing, with the values all within the range of 0.5% to 1.0%. However, at 800 °C, significant variations in elongation are observed among the microstructures. Specifically, an increase in equiaxed γ phase content correlates with enhanced alloy elongation. Compared to samples treated at 1270 °C, those treated at 1220 °C exhibit a 280% increase in elongation, while those treated at 1170 °C show a 480% increase. This enhancement is attributed to the improved deformability of the equiaxed γ phase at elevated temperatures. Additionally, greater activation of dislocations within the β_o phase occurs, while the γ/γ and α₂/γ interfaces impede the movement of twins and dislocations. The study further provides a comprehensive discussion on the evolution behavior and patterns of different heat-treated microstructures, emphasizing their correlation with mechanical properties.