Yes, we use those for our "More Text" expanders in the exploration tool http://build.fluidproject.org/prefsEditors/demos/explorationTool/

We can get away from the browser support issues there because it's okay to have them not toggle. I'm not sure the same is true for PMT/PCP unfortunately. You're right that the support is pretty weak at the moment, with no support form IE or Firefox. http://caniuse.com/#search=details I don't know what the intended browser support is for them though. Perhaps @kaspermarkus could enlighten me on that. @chrispetsos you're right though that it would be great to switch to native elements when we can.