Does CustomPress maintain revisions?

I'm creating a HR Policy website and I need to keep a revision history so that we can go back and see what a policy looked like on a given date.

I'm using CustomPress to create certain fields so that they are consistent in the documents, e.g. policy, scope, version number, effective date etc.

I noticed that the custom fields do not change when I do a roll back to a previous revision of the post.

Is this not possible in CustomPress or is it a setting that I am overlooking?

Many thanks
Ian.