This would be great, in particular if it can use the "--jobs" flag of submodule init to clone multiple submodules in parallel

For anyone still suffering from this like me, I came up with a bash script to do this instead:

modules=(
    submodule1
#   ...
)

for module in "${modules[@]}"
do
  echo "deiniting $module"
  git submodule deinit "$module"
  cat >> .git/config << EOF
[submodule "$module"]
        active = false
EOF
done