OT with Bluebox

I’ve just got back on the OT and trying to use it with my Bluebox but suffering from latency from the BB when combining samples on the OT and a ND on a Thru machine which is routed to the OT via the Out2 on the BB.

I get latency on the Thru machine. Is anyone else using a BB in this way and is there no solution other than to just route the ND straight to the OT or get an analogue mixer?

Thanks.