Dovecot 2.4: dirsize removed - alternative for physical size quotas?

We're upgrading our servers from Dovecot 2.3 to 2.4 and hit an issue with the dirsize driver removal. In 2.3, we switched from "maildir" to "dirsize" quota driver because maildir counts virtual (RFC822) sizes. This caused mailboxes to appear full before reaching actual disk limits

• base64-encoded attachments make the virtual size larger than physical disk usage. For example, 8GB actual usage could show as 10GB+ in quota calculations. The dirsize driver solved this by calculating quota from actual file sizes on disk. In 2.4, dirsize is removed with the note "use quota-count instead." However, the count driver requires quota_vsizes=yes, which uses virtual sizes - the same problem we had with maildir. What's the intended solution in 2.4 for tracking quota based on physical disk usage rather than virtual message sizes?

The available drivers seem to be:

• count: requires virtual sizes
• maildir: also uses virtual sizes via maildirsize
• fs: requires OS-level per-user filesystem quotas

Is there a way to configure count for physical sizes? Appreciate any guidance.