However, applying a cautionary principle, I would really prefer to find a detailed description of what ingredients are these meat cultures being supplied with during growth.

For example, cow meat is theoretically healthy but the previous outbreak of BSE started with cow feed that included other cow parts.

In the same way sea fish is theoretically healthy, however aquaculture fish feed includes a large portion of fishmeal which is again grinded dead fish guts and bones. The nutrional value of this (lower omega fatty acids content?) is to me not clear and the impact of this is perhaps insuficiently studied (Happy to read any sources others may suggest).

I am not arguing that a lab grown muscle cell is different from a muscle cell appended to a chicken. But I would very much like to see more detail on the supply chain of how that muscle cell is provided with nutrients.