How to handle on-purpose NaN entries in x_o? #1717
Description
We recently introduced a NaN / infinite check on x_o in process_x, see #1701
When using padding with NaNs, e.g., for permutation invariant trial embeddings, this causes a ValueError at inference time.
The corresponding test in tests/embedding_net_test.py::test_npe_with_with_iid_embedding_varying_num_trials has been marked as xfail.
Task: find a way to allow both, strict checks for NaNs to avoid silent failures in NPE, and padding with NaNs when needed, e.g., via kwarg? Or we recommend implementing the trial-embeddings without using the Posterior interface.