Thanks for continuing to respond, appreciated. I may not have articulated the issue as well as I could have. Let me simplify:
1. I am using an output set to DLY/REV to get only the FX isolated
2. I used an external FX loop for delay and reverb etc
3. When using internal FX on one of the last 2 modules I can hear them through the DLY/REV out as expected and can switch between then fine
4. However if I set my external FX loop in either of the last 2 modules, it only comes through the DLY/REV output when the other is enabled and has an effect in it
5. The only way I have found to work around this is to turn the routing in rig settings to somewhere around 50%, but this means dry signal bleeding into the DLY/REV output at all times even when the modules are off
Conclusion: Why is it not possible to use an external loop in one of the last 2 modules and also hear it through the DLY/REV out without having the other module also populated with an internal effect?