Clutch cable bolt

May be a stupid question but here goes. While trying to figure out a better way to actuate the clutch, I noticed that the tapped hole in the engine case
for the clutch ajusting bolt goes all the way through. If you take the bolt out you will be left with a hole in your engine case. Does this hole need to be sealed to prevent any type of vacuum leaks? I noticed no sealer on the bolt
and it wasn't even very tight.

Thanks for the tip. I'll just plug the hole as I am going to make a bracket that will hold the adjuster and a bearing pulley to run the cable around. I'll tin/solder the cable and use a real pinch bolt in place of the tiny little brass cable stop. The quality of these kits just makes me laugh sometimes.