the popping at high rpm hasn't anything to do with valve float...that is from tuning...and the video of the import is also purely tuning...those turbo cars will have the spark timing very retarded to light off the fuel mixture IN the exhaust manifold to spool the turbo
Too much injector pulsewidth at high rpm causes the FDCS signals to overlap, and the PCM will cut PW (to 0.6ms on every other signal) to prevent signal overlap.
symptoms of valve float are: loss of boost, loss of power & piston to valve contact (usually resulting in broken rocker arms &/or bent pushrods)
our valves typically don't float from "rpm"...but are more likely to float from boost/drive pressure exceeding the seat load of the valve.
The back of the valve is approx 1.5-1.6"...so if you were running 60psi of boost for example...you'd have 113 "pounds" trying to open the valve, with no aid from the rocker/cam.
the factory specs are 71-79lbs of seat pressure @ 1.833" installed height, for both I&E valves...so the factory valves will try to open (with no consideration to rpm) with just under 40psi of boost.
the higher the boost...the more seat load you'll need to prevent float...but it's calculable, for the most part. boost multiplied by 1.88 should give you a ballpark seat load...
HEUI trucks shouldn't have to worry about the rpm side of things.
