Currently we have no way of tracking reading speed in LingQ other than using external tools (eg. a timer). Using the app on different platforms makes this even harder (eg. iOS users can't rely on screen time retrospectively as these get deleted every 2 weeks). Simply tracking how much time a user spends in the reading window of any content would solve this issue as LingQ is already tracking words read - so the user could on their own calculate or there could be a simple calculated "reading speed" added to the stastics.
The whole reason I started using LingQ over other apps was the ability to track my reading & vocab without any burdensome manual work. While this may be a minority, I think a sufficient chunk of users are interested in the tracking side of LingQ, seeing their streaks & known words increase over time, it'd be nice to also see how we improve our reading speed. Past 10-15k known words I feel less interested in the size of my vocabulary and more curious about my reading speed, I can clearly feel it improved but I can't check my past data unfortunately.