Stuff like this is great! And you said you mentioned you are primarily doing it for timeseries data - then you can easily batch writes to handle high volume throughput too!
We did this with S3 as the storage engine, 100M+ records for $10/day: https://www.youtube.com/watch?v=x_WqBuEA7s8
And discord had a very nice article on this as well: https://blog.discordapp.com/how-discord-stores-billions-of-m...
Great work, I think there is a lot of exciting stuff you can add to it!