Front foot impossible is indeed a rare bird but still considered canon as far as I’m concerned. Ocean Howell was a prominent practitioner but that was nearly three decades ago and few have stepped up since. Are they in danger of extinction?
How about the switch chain wallet ie switchstance varial flip? Bit of a head turner, maybe some ill received grumblings under an observers breath, perhaps a tinge of jealousy? (you never know!), uncommon for certain but no ones gonna focus your board over that one.
Various heelflip variations also fit the bill, not too many people doing frontside heelflips (that one is a level ten out of ten difficulty) or fakie varial heel on flat. Shoutout Mike Hayes but if you rip a lazerflip for funsies you’re def going to jail so let’s keep this discussion within the bounds of civil society.
What flat ground trick is just not happening midline these days?