Bike typing animation performance at bottom of window?

I’ve had one report that Bike’s typing animation gets slower when you are typing at the bottom of a window.

The uncannily smooth typing experience that Bike demonstrates in the beginning of a document seems to go away a you get to the bottom of the screen and start to scroll as you type

I can’t seem to reproduce this or maybe am misunderstanding the report. Has anyone else noticed a slowing of the typing animation?