I am perhaps the last person to composite mod their Spectrum. I dug it out to demonstrate 80s computing to the children (much fun was had by all), and while our TV does take [UV]HF in, it's probably going to be the last one that does. So, I gritted my teeth, committed sacrilege on the machine I grew up with, and did the mod.
Of course, I did the reversible version, unsoldering leads rather than cutting them. Even then, I was extremely twitchy about lifting a pad or whatever. Interestingly, though, no hardware change would have been necessary. As an experiment, I just tapped into the composite signal being fed into the modulator (with an alligator clip!), and... it works fine on the display. The modulator doesn't do anything sufficiently bad to make my display fail. The business of disconnecting the existing modulator and routing the signal out through the TV out socket seems to be largely for convenience. And for me... convenience won in the end.
Of course, resurrecting the Spectrum didn't involve just twiddling the video output. After a couple of decades (at least) since last use, I had to replace the grotty old keyboard membrane. It turns out my muscle memory for the Spectrum keywords hasn't gone away, which is midldy scary. I also bought a SMART card to load memory images into the Spectrum, which is both cheap and effective. It's all pretty cool, although admittedly not as convenient as an emulator.