I don't know why people call ancient feature a "security hole".  I And the only time it's actually a risk is if you go to drop the proc. You can't define which part to drop.  It's all the procs in the numbered "group".

We didn't use it for versioning back in the day.  We used it to number steps in an execution order.  I say "we" but it wasn't me.  It was someone else's idea at a company I worked at a very long time ago.  It did help de-declutter things a bit but I still wouldn't use it even if it weren't deprecated because you can't drop a single numbered part.  You can, however, alter a numbered part.