The lengthy and complex manufacturing process makes it challenging to implement drastic modifications to the production of CAR-T cells. Changing things like the cell culture medium or adding metabolite adjustments are challenging to incorporate on a large scale. These changes must be carefully evaluated to ensure they do not compromise the quality or safety of the treatment, which would lengthen the already long manufacturing process. Any significant changes made during the process can prolong production time for patients in urgent need of an emergency treatment. The use of oncolytic viruses presents a unique challenge in the context of safety, particularly concerning the risk of CRS. Mitigating the chance of CRS requires careful consideration of treatment timing and dosing specific to the patient, which will extend manufacturing times further. The cost of incorporating changes in T cell production is also a concern. Development of autologous T cells is already expensive, although allogeneic T cell production remains a favorable solution. Regardless, implementing the discussed changes of T cell persistence will require costly upgrades to manufacturing facilities and equipment.