This is now fast enough to use 7 character vanity prefixes, which are the full length of the short sha displayed in most Github tooling. Link to sample repository showing this, or just add a screenshot?

Probably should use a funnier hash than beef321 if so. Though, I really don't want to encourage people to do this in reality.
Generated via
#!/bin/bash
GITBRUTE="$(PWD)/bin/gitbrute"
SAMPLEDIR="$(PWD)/sample"
PREFIX="beef321"
mkdir -p "$SAMPLEDIR"
cd "$SAMPLEDIR" || exit 1
git init
for i in {1..6}
do
echo "aaa" >> a.txt
git add a.txt && git commit -m "made commit #$i"
$GITBRUTE -prefix "$PREFIX"
done