These windows are too large for the Testors window stuff. For larger windows, even if you can bridge the window, it sags as it dries. I could try putting the tape on the back like I did with the epoxy.
However, I find another problem with the Testors windows. I find them a bit too fragile for good masking. Ordinarily I put a little piece of tape on the back to prevent paint from getting inside fuselage, and wait till the painting is done before applying the windows with that stuff. Then the problem is getting the masking tape off and out of the fuselage with the model complete. With the epoxy, it is firm and strong enough to mask, and I pulled the tape on the inside off before I closed up the fuselage.