disk average 30% lower than actual disk usage

Hello @mdw,
Welcome to the forum!

Please try to create this piece using this instruction:

The mapping between satelliteID and blobs you may find there:

Then monitor your logs, if your assumption is correct, the retain process should continue and move all deleted data to the trash. Please note - the retain process (known as a Garbage Collector) needs several loops to move all deleted data to the trash due to how the Bloom’s filter works.