I've coined the term "barely-flex" for nibs like these, where you don't normally see any flex, but you can get some if you press down with a Gorilla Hand. From where I sit, it's a stunt or a novelty, not something useful. The supposedly "semi-flex" nib that came with my Wahl-Eversharp Skyline Technic fits into a similar category, as does the FPR flex nib.
The most flexible nib I've seen on a recent production factory pen was a Lamy 2000, if you can believe it.
but I think we have seen better I have yet to get my hands on a C912 FA nib and pen... more on the nib than the pen... then look for a way to actually find the reasons why Pilot made such a nib