LDAP scheme for Dovecot

I use an LDAP server for user administration, the users can manage themselves with the LDAP Account Manager (LAM). I would like to give the possibility to be able to define the quota per user.

LAM provides support for certain schemes, but the qmail scheme is missing in the free variant. So I used the Courier scheme. Now, while LAM correctly stores the value in bytes, it appends the letter S. Unfortunately, the mail server Dovecot cannot do anything with this letter S.

Is there a better scheme for Dovecot? I haven't found any until now. Or can I remove the letter S at the end in the Dovecot configuration file via regex?