MANIFEST file grows forever if the DB is not closed and re-opened

I have a scenario where I need to keep the DB open for a long time (say months) and process continuous updates that replace old values. So my overall data size is not changing. I have verified this: the total size of the data files is constant over time. However, the MANIFEST file size keeps growing, as compactions are periodically happening. This forces me to close/open the database periodically, since during an open, the log-structured MANIFEST file is processed and compacted.

Shouldn't there be an upper sizee limit for the MANIFEST file or some period after which the MANIFEST file is compacted, without requiring a close/open of the database?