To answer this in case anyone has a similar issue in the future; it turns out the model I was trying to convert did not include any float64 operations in its architecture, but the problems were introduced in the additional processing layers compiled in the model. Once I loaded it and resaved the model as is, these processing layers were stripped off automatically and I was able to convert to TFLite without issues.

Now I just need to figure out what processing was performed in those layers to obtain the same results.