Again, there are probably tunables and practices specific to MyRocks that we just didn't consider. We just didn't want to pursue this any further.
Mariadb has an example walkthrough on this: https://mariadb.com/kb/en/library/partition-maintenance/#par... .
The only change that I'd recommend considering, is we use partition by list, instead of range, and keep a weeks worth of daily future partitions. This makes it so you don't have to reorganize the table. On the other hand it means if you get future data it can fail and if your partition jobs have issues for a week you can fail to load data all together.
Using partitions for time series data help also due to partition pruning, https://dev.mysql.com/doc/refman/5.7/en/partitioning-pruning... .