As you say, compliance is not certain. People will find their way around it and (hopefully) use common sense to determine the speed they feel good rolling at.
We have many speed limits in Ecuador, but not much enforcing, either. Besides the fact that most people here are really bad drivers and accidents occur no matter how slow the law says they should drive, most parts are limited by nature, anyway. The fastest I ever got as 180 km/h during the lockdowns in 2020. I had a special permit (bakers are first necessity, so I was allowed to deliver to my clients). That speed was only possible as nobody else was on the street, and the road was straight for 1km - that's a lot in Ecuador. Usually, it's curves everywhere.
Just like with the black ice mountain road - of course you can drive 100 km/h, but you'll do it only once.