We are actually doing something similar, look at the "IPA Invoice Processor" flow.
We have introduced a Power Apps to configure the starter kit and where we store the mapping between the resulting invoice and the labels for each model and we store this in a custom entity "IPA Provider".
This information is retrieved in the flow with "Get Provider Information" including the model to call.
Then we call "Call a bound action" with this model dynamically.
Finally, we use complex formulas to dynamically retrieve the extracted data from the json output.