Lately I’ve not encountered any lines, or anyone at all, at Colombia Migración/Banjercito. I’ve had to ring the bell for the Migración officer the last two visits. On a weekday you should get through there in 15-30 minutes max. And MEX2 is in better shape as they get it built up for increasing traffic. If you want to avoid the SuperSlab MEX80 libre you could take HWY 1 through Anáhuac to the Monterrey Periferico 40 libre (I did last week) but it’s about as boring a two-lane as you’ll ever ride. On the 690 I’d just stick to 2/85 Libres.