maybe i am wrong, but isn't it even better, to use BS components instead of "own" components. for example clamscan. ispconfig uses clamscan in /home/ispconfig/tools/clamscan/... (if i remember correct). if there is a newer version of clamscan, i have to wait for a ispconfig update and to update my server. i am using some "self-patched" scripts, so i have to update to a never ISPConfig version and then i have to "re-apply" all the patches (and not to forget any of them). this means i do not do any ispconfig update if i don't need to do it. if ispconfig uses the (in my case) "debian" clamscan i only have to do Code: aptitude update aptitude upgrade to have the newest clamscan installed. i think, this is even easier to do and no one had to wait until there is a new version of ispconfig (and the developer haven't to make a update because there is a never version of clamscan).
There are two things that you should consider. First, debian does not update your clamsac to the latest version, they just patch clamscan to fix bugs but they do not offer always the latest version. The other thing is, that we support many different linux distributions and not every linux distribution makes it so easy to update and install clamd and clamscan. But generally it is a good idea to support the native applications of the linux distributions and I'am working on this already for some time.