Routing with a Focusrite Saffire PRO 40

[Deadweight]

Hi guys. Im trying to create some kemper profiles to share and what I'm trying to do is bring 2 sm57's into reaper via a Saffire pro 40, put some low and high pass filters on them and then use the fredman technique to create one sound and route that back to the Kemper to profile it, meanwhile monitoring the sound on the track that is coming back from the Kemper. Is this possible? I can't seem to figure it out. I either get feedback loops or no sound at all
huge thanks for any help with this!