Hey George, thank you for your interest in my issue.
I was able to get a bit further with the help of a discussion in a github issue here:
github<dot>com/tensorflow/models/issues/9371 (“link” to issue, apparently i am not allowed to include links in my post)
My original error was to take the wrong script to export my checkpoints into saved_model format. I was using exporter_main_v2.py instead of export_tflite_graph_tf2.py. Since then the conversion and inference step actually works (in some manner as it terminates without error)
The resulting tflite is too small though as it only reaches 440 bytes. Apparently this is an issue when using wrong tensorflow versions but even after a fresh install of tensorflow in a virtual env the problem remains the same. This so far is without integer quantization.