Hi, why don't you use configSource attribute in your web.config to move to another config file the CAB configuration?
For Example:
<?xml version="1.0"?>
<configuration>
    <configSections>
        <section name="cachingConfiguration" type="Microsoft.Practices.EnterpriseLibrary.Caching.Configuration.CacheManagerSettings, Microsoft.Practices.EnterpriseLibrary.Caching, Version=4.1.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
         ....
</configSections>
 <cachingConfiguration configSource="Config\Caching.config" />
And then, in Config\Caching.config:
<?xml version="1.0" encoding="utf-8" ?>
<cachingConfiguration defaultCacheManager="DefaultCacheManager">
    <cacheManagers>
        <add name="DefaultCacheManager"
             expirationPollFrequencyInSeconds="60"
             maximumElementsInCacheBeforeScavenging="1000"
             numberToRemoveWhenScavenging="10"
             backingStoreName="Null Storage"
             type="Microsoft.Practices.EnterpriseLibrary.Caching.CacheManager, Microsoft.Practices.EnterpriseLibrary.Caching, Version=4.1.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
..
As far as I know, you can use a separate config file for each configSection in your web.config
s.