Different box sets for posts and for 404 pages?

Quick question. The Platform theme (non-paid version, anyway) uses the same box set with both posts pages and with 404 pages (“Posts Page and 404 Box-Set. Posts pages and similar pages (404) will use this box-set ID”); and, with BuddyPress, for the Activity stream as well.

Is there any way of allocating different box sets independently to each of these three? in the Pro version, for example?

Thanks ??