The Sympl command line now has support for managing FTP configurations across all branches of Sympl. This was pushed to the testing branch some time ago, after some hard work implementing it by contributor Doug Targett, but only just reached stable for Buster and Stretch along with a number of unrelated bugfixes.
Secondly, In a few cases, you may need to make custom additions to the Apache configuration files to support interaction with other services, such as identifying the remote IP address from a proxy service.
This can be done by editing the configuration file itself but this means Sympl won't update the configuration automatically any more, or you can adjust the templates but that prevents the templates from being updated.
As of sympl-web version 9.200909 and 10.200909 there is new functionality to include optional configuration files on a per-domain basis.
To use this, you need only create files in the /srv/example.com/config/apache.d/ with the .conf extension with the relevant Apache directives in, then reload Apache and the content of the files will then be included at the end of each configured domain.
As with any direct configuration changes, care should of course be taken, but this should make configuration easier in a few situations.
For more information on this, check the Sympl Documentation, or discuss this on the Sympl Forum!