I think it would be a mistake to think about this as additive. The interactions that CBSA has with the public are qualitatively different and are quantitatively different from that of the RCMP. Also, the CBSA has a very different training regimen. It is, I would say, much more robust than what the RCMP does at depot.
Even in most cases when there is, for instance, an arrest to be carried out, CBSA will call in the RCMP to carry out that arrest. CBSA will usually engage only in the detention piece, so I think you won't see the types of extremely resource-intensive and onerous investigations that you might see with the RCMP.