On chicken pecks and why "8" is the only number that gets used to replace a syllabic rime.

I've noticed that, in the context of email and online slang/abbreviations, the character "8" is the only number or character that gets used to replace a phonological rime (a nucleus plus a coda). Most other replacements either replace whole syllables, or just consonant clusters.

For example (from Wikipedia's "List of Internet slang phrases")
2L8 -- too late
GR8 -- great
H8 — Hate
L8R — Later (sometimes abbreviated to L8ER)
M8 — Mate
sk8/sk8r — skate/skater
W8 — Wait

The numbers "2" and "4" can replace whole words:
2U2 — To you too
G2G — 'Got to go' or 'Good to go
L2P — Learn to play
N2M — Not(hing) too much
N2B — Not too bad
P2P — Peer to peer
T4P - Tell for people

Here is an example of each character replacing a whole syllable:
NE1 — "Anyone" = an.y.one

"X" replaces a consonant cluster in a few cases, but not the nuclei of the rime:
KTHX — OK, thanks
TH(N)X, TNX or TX — Thanks

Why is "8" the only number that gets used to replace a whole rime (a nucleus plus a coda)? My guess is that it's because, of the 13 basic number names in English, only two begin with a vowel ("8" and "11"). The name for "11" is itself 3 syllables long, so it's out as a candidate. The name for "8" is the only single syllable number name that starts with a vowel. So it's the only one that is eligible for replacing a rime.

English Number names
zero
one
two
three
four
five
six
seven
eight
nine
ten
eleven
twelve

So, the constraints on using characters to replace a rime are 1) must be pronounced as a single syllable and 2) start with a vowel. How many keyboard characters meet these two criteria? Letter names = 2. If we tried to use them to replace rimes, would the usage catch on?

"F" and "X" are the only letter names that follows the VC(C) pattern of "8", so "x" it could be used to replace "-ecks/-eks" for example, but how many words end in that?

Here's a valiant try:
chicken pecks -- chicken pX??

Presumably "@" could replace any "-at" rime and maybe (stretching here) just maybe you could get "&" to replace "-and". Do people do either?
cat = c@
sat = s@
flat = fl@
sand = s&
land = l&