Number of concurrent requests in streamlit

I have created a streamlit app that forecasts covid cases and want to deploy it to google cloud run, but also want to remain in the free tier at the same time. As the GCP pricing calculator has a field for the number of concurrent requests per docker container, I want to know how many streamlit can handle, because changing this metric to a higher value makes the price a LOT lower and makes it easier for me to stay within the free tier.

Also, this is unrelated, but as this is my first time on GCP, I have a question related to Cloud Run. Cloud Run needs a docker image only from GCR, but GCR does not have a free tier. But GCR uses Google Cloud Storage to store the container image, and the free tier for Cloud Storage is 5GB. So does this mean that I can use any container image less that 5GB, upload it to GCR and use it in Cloud Run, without incurring any costs?