As I've said, several times already, if you have problems with this feature, just set the "Verbosity" slider one notch down, and it will be as before, with no readout.
It seems the problem can't be really fixed, without making the readout useless (updating it with less frequency would fix it, but it won't be very useful then).
We are re-writing that feature entirely, to use a completely different method, much better-looking and totally unaffecting fps, even in full screen. Stay tuned for another update and just turn the Verbosity slider one notch down in the meantime.