Possible to duplicate shot tracks

Multiple shot tracks are a problem source, and UE seems to try and pre-empt them by disabling the menu option to add a second one when one is already in there. Duplication, however, is still permitted, thus creating the problem where a sequence can play two shots simultaneously, creating issues with actor lifetime and such.

Steps to Reproduce

1. Create a shot track in a level sequence. Observe that on clicking the "+ ADD" button, the "Shot Track" option is now greyed out.
2. Right click on the shot track and press "Duplicate". Observe that it's possible.