The BRP ruleset implements the 2010 edition of the Basic Roleplaying rules. IMO any rule that is present in that edition is legit for implementation in the BRP ruleset. The official ruleset implements the 2010 edition (which is still available at chaosiums site as "BRP Classic" https://www.chaosium.com/brp-classic/), so any rule that exists in that edition could (should?) be supported by Smiteworks.

