I hadn't noticed that... Pretty neat!
I remember seeing something a while ago, but can't remember know what it was...but it had a flipper held on by a screw, so it could be removed or added on.
This has got me thinking though, i kinda want to grind the flipper off my Bestech Eskra now. I middle finger flick that thing 99% of the time anyway
(only problem is, it's a coated blade)