Are these experiments logged too (with the train-valid curves, etc)?

Yes every run is log as a new experiment (with it's own set of HP). Do notice that the execution itself is done by the "trains-agent". Meaning the HP process creates experiments with new set of HP an dputs them into the execution queue, then trains-agent pulls them from the queue and starts executing them. You can have multiple trains-agent on as many machines as you like with specific GPUs etc. each one will pull a single experiment and execute it, once it is done it will pull the next one etc.

SourSwallow36 how are you thinking of running those HP tests?