Long execution times when retrieving hyperdrive results

```python
exp = Experiment(ws, 'hyperdrive')
exp_runs = exp.get_runs()
run_id = '#hyperdrive_run_id'
for run in exp_runs:
if run.id == run_id:
break

# this takes quite some time
hyperparams_set = run.get_hyperparameters()
metrics = run.get_metrics()
```

We notice long execution times (of the order of ~5 minutes) when retrieving hyperdrive results (hyperparameter results). We log simple values and some lists during the hyperdrive step execution, which does not have more than 300 child runs. Is this the expected behaviour?