Not leaving the existing controller in with the QBone also doing emulated RL will create an address conflict, though *maybe* it will work if the Qbone is in front of the RLV on the bus? But certainly best to change the jumpers/switches on the existing RLV to a secondary controller address if you want to leave it in place.
BTW, I did have some issues a few months back with my Qbones with respect to interrupts where I found it best to put the QBone at the end of the chain on a microVAX. I also had an issue where my RLV12 in my micro PDP-11 would not boot using the code provided in dl.lst, but never investigated it fully, as the RLV12 would boot fine using my real boot ROMs.
JRJ