Is training a requirement to use apex O1 mode?

Hi.

I am trying to use apex only for inferences with an existing model that was trained with FP32 (with no mixed precision, and no apex support). But I’m wondering if what I’m doing is wrong. I can’t find in the documentation if apex can be used only for inferences without re-training the model.
I cannot re-train my model. I posted this question here: https://github.com/NVIDIA/apex/issues/750 but I’m confused about the feedback I got. Also It’d be really good if I can find something that is supported by the documentation to make sure what I’m doing is possible.

Thanks
Damian