Ever growing IPS repositories

I have noticed that every time a new SRU is released my local repo grows when I update it.I now realize that this may makes sense, but if possible I'd rather have an option such as:

For every new SRU create a new local repository based on the initial "release" version (and not the previous SRU) and apply the most recent SRU.
In case it's necessary to revert back to some older BE based on an older SRU, revert to the old repository as well.

Although the total space shall be approximately the same of a single repository with a series of SRUs, at least I could gain more granularity if I need to make room on a main repo system, moving away olther repo+SRUs elsewhere, right?