The way I see it such functionality does not exist in CA PPM.
If I take an object with timescaled values as the data source of a portlet like assignments I do not see the blob fields in the list of fields available for the layout.
If I query the prassignment for the blob fields I get blobs and there is no option to turn them into clear data
I if use a system provider specifically prepared for that like Team Allocations I do get the normally readable data fields but again I do not see the blob fields. However, I do have the option to add a virtual timescaled field
which does not exist for a query based portlet
but exists for an object based portlet like on base on Assigments. However, if I try to add such a field
it is not possible as no value attributes are available like in a specially prepared system data provider.
When looking at the portlets that can display timescaled data I experience that the data is limited to the time range is system timeslices. My conclusion from that is that those system data providers do not have the blob cracker built it, but behind the scenes they do get the data for display with queries from the system slices. While using action trace when storing data it can be seen that they use java code to write directly to the blobs.