I found that if you tapped the jump button (spacebar) while in midair from jumping, you would perform a glide effect. I also found code PlayerConnection.class that suggests that Spigot is fully capable of intercepting packets for both the jump-glide feature, and swapping of main hand/off hand items. Could these events possibly be added (ex: "PlayerStartFallFlyingEvent", "PlayerSwapHandsEvent")?