The standard walking speed for soma is 1.5 pixels per frame, jumping does not alter his speed. Walking up in stairs makes him slightly slower, so It is advisable to jump rather than walking upstairs.
Backdashing is unlocked at the very start of the game by getting the grave keeper soul, it's faster than regular walk, although it has some lag frames at the start and end. If you are good at mashing it still is slightly faster than just walking.
In order to make backdashing faster, it is very advisable to cancel the end lag frames, in order to do that, you need to jump at the end of the animation. Also note that you'll want to do the shortest possible hop, in order to backdash again soon after. This is probably going to be your most used source of mobility for most of the game, so even if it's pretty tough on the hands, it's good to at least try it.
I suck at blade dancing so I'll leave that one for someone else :)
Backdash cancelling into kicker skeleton
It is actually faster to do a double jump into kicker skeleton dive kick after doing a backdash, since the speed from the kicker skeleton is a bit faster than backdashing. Note, however, that you'll want to cancel the lag when you hit the ground from the dive kick, to do that tap L with either a rush soul or the giant bat soul. Kicker skeleton can be found in floating gardens secret room. No current category uses this tech, since its a random drop in an area far from early game route, and once you get there you have better movement options.
Rush souls (curly, devil and manticore), in addition to being the best offensive option in the game are very good for movement. It takes 60 frames to start moving, and slowly builds up speed, so its generally used in long corridors. Note however it uses a lot of MP, so breaking candles in the way to restore some might be a good idea.
Black panther is the best form of movement in the game, no start nor end lag, it moves considerably faster than walking (4 pixels per frame) and it consumes almost no MP. The downside is that you only get it after defeating Graham, at the very end of the game. Therefore it's not used in any of the any% categories.
|Walking||1.5||Slower on slopes|
|Backdash||Depends||Struggles with going in slopes, has end frames lag|
|Backdash cancelling||Depends, up to 2.4 in TAS*||*Depends on cancelling jumps with guardian souls|
|Blade dancing||Depends, up to 2.2 in TAS*||*Depends on the weapon used|
|Backdash + kicker||4 during the kicker skeleton dive||N/A|
|Rush souls||~2 at the start, up to ~6||Takes about 60 frames to start, all souls have the same speed|