It’s true that most of us find it somewhat difficult to understand what native speakers say as the native speakers pronounce words quickly and together. So, we’re not able to understand the dialogue of English movies. Their accent is so fast that we can’t grasp what they say. But we...
I wrote an answer a while back about the pronunciation of xeno- that talks about some of the -e_o- combining forms: Pronunciation of “xeno-” Perhaps the "trisyllabic laxing" pattern is mostly a historical relic at this point, and so people don't feel any strong pressure to use pronu...