B Hero Corner Boosting

Corner Boosting (will update as I find more.)

I put 32 for a lot of things that are less then a flat dropoff for 32, plan accordingly.

Battle Room:
Move 18 px in 2/60 frames.
Drop a bomb going into the first hole (32)

Hyper Room:
It barely matters whether you jump or drop a bomb near the start.  I think dropping the bomb saves 2 frames.
I think dropping the bomb onto the second moving floor probably saves ~4 frames as well if it's practical.

Heavy Room:
For the big fall, jump and land just short of the hole, then drop a bomb to eject forward and preserve downward acceleration.  (32?)

Sky Room:
Falling after the heart (32)
Falling after the key card (32)

Blue Cave:
N/A

Hole Lake:

Move 10 px in 2/60 frames.
A straight drop off gains about 48 px after the normal 10 is subtracted off.
A 45 degree drop off gains about 24 px after the normal 10 is subtracted off.

Go over the first ledge (opening) at the top (48)
Go up and left and get a boost off the ceiling (24)
Go over the top of the next two brown pillars (48 + 48)
Go up and right and slip down over the end flat part of the ledge (48)
Right after this, go down and right and slip off again quickly (24)
Right after this slip over the brown pillar (48)
Go over the top of the next 4 brown pillars (48+48+48+48)
Go over the top of the left edge of the second stair of the rock structure (48)
Go over a box (48)
Go up and left and slip over the last edge near the crab (24)

600 px saved

~120 (/60 fps) frames saved.

Red Cave:
First ledge (32)

Dark Wood:
N/A

Dragon Road:
Two small boosts possible at end (10 + 10)  (saves literally 2 frames, might be better off just getting a good angle into boss.)

Clown Valley:
Boost over the top if you're not making the hard jump (32)

Great Rock:
N/A

Fog Route:
Over the small ledge near the beginning (32)

Groog Hills:
Over the first red thing (32)

Bubble Hole:
Over the Structure near the beginning (32)
Off the ledge after the warp (32)

Erars Lake:

The floor doesn't do anything.
Go over the first two huge objects (48 + 48)
Go over the pillar with the heart (48)
Go over the structure on the right wall (48)
Go over the boxes (48)
Go over either the pillar on the left or right just after the boxes (48)
Prepare for the Manta
Two tricky fast boosts off the left or right after the warp (48+48)
One boost off the hole with bubbles (48)
One boost off the right box or the hole (48)
One boost off the left box (48)

528 px saved

~105.6 (/60 fps) frames saved.

Waterway:
N/A

Rock N Road:
Right after the blue enemies (32)
Over the first pipe (32)
Over the second pipe (32)
Over the short ledge (32)

Water Pool:
N/A

Warp Room:
After first warp (32)
After last warp (32)

Dark Prison:
After second crystal (32)

Killer Gate:
It's possible but extremely impractical.

Spiral Tower:
N/A

Snake Route:
N/A

Hades Crater:
N/A

Magma Lake:
N/A

Magma Dam:
First ledge (32)
Bottom of the lavafall (32)

Crysta Hole:
First ledge (32)

Death Temple:
N/A

Death Road:
One near the beginning (32)
One right after the portal (32)

Float Zone:
Ledge at the beginning (32)

Aqua Tank:
N/A

Aqua Way:
4 ground ledges inside the fish: (48+48+48+48)
38 frames.

Hard Coaster:
N/A

Dark Maze:
N/A

Mad Coaster:
None worth attempting
Sliding over the last ledge would be optimal but risky.

Move Stone:
On way to second block over center stairs (32)

Hopper Land:
Move 18 px in 2/60 frames.
You should be able to get 4 while holding right.  The third is over the top of a red platform. (32+32+32+32)

Junfalls:
N/A

Cool Cave:
N/A

Snowland:
Over the first ice tree (32)
Over the giant ice blocks (32)

Storm Valley:

Snow Circuit:

Heaven Sky:
(Travel at 18px per 2/60 frames)
Over/Under the first ledge (32)
Over a giant statue on the left or right (32)
Over a brown suspended platform (32)
Over a brown bar (32)
Over the top of the last platform (32)

18 frames saved (/60)

Eye Snake:
N/A

Air Room:
You can get one at the start, it's a bit risky (32)

Zero G Room:
N/A

Mirror Room:
Beginning of Level (32)
Ledge before falling (32)
Right by the enemy MAYBE (32)