I saw on the forum eMClient that different people feel a lack of NAMESPACE support in particular because on that depends features such as Shared and Public Folders (eg for Dovecot).
If there was the ability to specify the name of “default namespace” when configuring IMAP (something that should not require much effort for programmers) would be possible for those who need to use the namespace to configure the same account several times each time specifying a different NAMESPACE.