In the configuration files, I am finding lines of the following form:
#referenced redirect rule, if commented, the configured redirect rule will be invalid
IncludeOptional /www/server/panel/vhost/apache/redirect/<sitename>/*.conf
I have found that for several of the sites, there are many files matching the pattern, even though only one rule is intended for each site.
in some cases, there are large groups of files all identical to each other.