Saw on BitBucket today a user asking for a feature to be added that would delete the updates in your updates folder in LaunchBox. So instead of Jason taking time out to have to add this to LB (if he would have bothered to I don't know). I did a quick search and found a nice easy tutorial on how to do so yourself using the built in task scheduler that Windows already comes with. Now while just navigating to the folder every so often and manually deleting these would probably truly be the easiest solution adding a little automation to your life to eliminate a mundane task isn't the worst thing. Basically just follow the instructions from the page on the link and you will be on your way to scheduling a monthly clean up of updates folder.
https://pureinfotech.com/delete-files-older-than-days-windows-10/