If it's a Viking QR pin, the nut trick won't work.
The aligning portion at the front of the pin is larger than the minor diameter of the 5/16x18 nut's thread. The nut won't get past it.
I'm pretty sure that OB makes a shaft for your cue. I suggest that you inquire.
To any CM that's not aware of how to accommodate the Viking pin, the answer is quite simple.
The 5/16x18 thrd. insert is drilled with a 17/64" drill-bit, either before or after installation. This opens the min. dia. of the insert's thrds. to clear the aligning portion and still leaves adequate threads to make a secure connection with the threads at the base of the pin. I've done it 100s of times.