As global demand for clean energy rises, proton-conducting fuel cells (PCFCs) have gained attention for their ability to operate at lower temperatures than oxygen-conducting solid oxide fuel cells (SOFCs). However, proton-conducting perovskites, such as barium zirconates and cerates, face significant challenges related to reproducibility and densification. This work explores the use of sintering additives like ZnO, CuO, and NiO as strategies to mitigate these issues. These additives simplify processing, lowering the sintering temperature, and promote grain growth, improving material density and reliability. Despite these benefits, a trade-off exists with reduced bulk proton conductivity by adding sintering aids, which can be partially restored through redox cycling techniques. The findings presented here underscore the critical role of sintering additives in advancing proton-conducting perovskite electrolytes and highlight the continuing need for optimized strategies to develop high-performance PCFCs capable of efficient operation at intermediate temperatures.