I've got my github configured to watch the Roger's repo. When I saw a Pull Request looking to change 125 files for a case change, I had to see what this is all about. I just skimmed this thread and tried to figure out why this is being requested.
So it appears it all comes down to use a library called Eigen. The problem library is just some guy's hacking on a library created by someone else. The Arduino port is already 2 or 3 revs behind. The Arduino port is version 3.3.2 released last year. The official code is 3.3.4 released in June of this year getting active changes as we speak.
Looking at the github of the ported library, it is a sub project requirement of something else. So it is obviously not the guys primary focus. It states right from the get go:
A port of the Eigen linear algebra library for Arduino
This is a port of Eigen 3.3.2. This is a very early version of this library and should be considered "in development". It has undergone limited testing on a Teensy 3.6 device.
Why would stm32duino care about this or why it does or doesn't work with Roger's core? The code isn't even from the official group who wrote Eigen. The author doesn't seem to care about trying to keep up with the core project. Who knows, maybe the issue has gone away in the official code? The Arduino code is clearly only tested on the teensy.
The core borderflight project has exactly 1 watcher. The sub project Eigen has exactly 2 watchers. This isn't a popular thing. Why do we give this type of thing so many pages of posts?
Please don't even consider this change Roger.