I think Mac is right. The copper will be stressed around the hole. You have to have something to run over two plates. You have no way of knowing if the solder with the flux formed a key inside the pipe to hold it. + you can get flux overrun if you force flux into the hole. The flux when mixed with water if its trapped in one place forms HCL. That eventually will cause a pinhole leak or blow the solder plug out a few years later. That happens a lot with sloppy sub contractor plumbers in a hurry getting paid per house.
They slop the flux into the coupling. When they charge the line the excess forms a gel in the water and sits there in the pipe eating at it.
Everything holds water and the hot flushes out the flux residue but the cold can't dissolve it. 5 years later leaks within a few inches of each joint start to crop up.
Technical information and statistics are made up on the spot 46% of the time.
