I have good reasons to believe this is hosted on Oracle's free tier. Apart from the fact that pinging pico.sh points to an Oracle IP, the 10TB limit is consistent with Oracle Free Tier's limit.

You are correct, we are also multi-cloud: https://pico.sh/regions

Good call. Oracle does charge somewhat reasonable $8.50/TB after the first 10TB/month. Despite my dislike of Oracle it's not a terrible choice for this until you get some serious traffic.