Small datapack that allows for the keepInventory gamerule to be applied to individual players on a server.

Give all players that are supposed to keep their inventories the tag 'keepInventory'. All other player will drop theirs on death.
The gamerule keepInventory must be set to true for this to work.

Since this is an early prototype and proof of concept, only items get dropped and not the XP.
I did not test this on a server. Feedback is welcome.

Do with this whatever you want as long as you don't claim it as your own.