Still a bit
by the OP.
I thought (obviously incorrectly) that it was common knowledge that in many parts of the world airline ops were performed at or above the trop..
The inflight “concerns” have been mentioned above - possibility of it getting warmer as you get higher above the trop, and the winds, but that’s about it.
I must admit at the pre-flight briefing stage where you might have 15 minutes or less to check out the details of a multi hour flight which has already been run through some fancy computers to optimize levels etc I I recall the tropopause levels along the route were down at 1001 of the things you might take an interest in.
En-route, especially if polar, then maybe the trop became of more interest..