The FM video certainly demonstrates the effect with the steel core.  (Do you consider Helicore "steel core"?)

My other concern however is the sounding point.  Doesn't the choice of sounding point also change the vibrating string length?  I know that a lot happens with sounding point choice:

pitch and tone effects

bowing technique to "sound" the individual string(s) particularly at higher tempos

My bottom line is ........ I find myself often changing the sounding point in response to artistic/technical demands of the music.  How do people stay in one place on sounding point?

The second issue is ........... shouldn't I expect the string sets from different manufacturers to possibly favor different sounding points to play and sound good?

Finally, should I expect to be changing left fingering for pitch in response to varying sounding points?