Well no one will tell you for sure. I bet every ballast (at least from respectable mfg) is designed minding it has to survive working with EOL lamp for some time. But of course you stress resonant circuit (capacitor and inductor) at the output.
BTW what is that especial fun with forcing EOL fluorescents? Orange light probably goes from stem glass melting and releasing some sodium ions into the discharge. Until it finally cracks or gets sucked in by vacuum. So the lamp momentary works LPS style
I did it may be a couple of times in school age, though electronic ballasts were still not widespread and effects on the magnetic were not that spectaculars. Typically, electrode support wire just melted to a ball and then lamp extinguished, but did not typically lose vacuum.