Maybe an explorer could be added so the player could get certain unobtainable items like hearts of the sea, cocoa beans, dripstone, etc.  

I think a reset for these new features would be great, also with the implementation of a nether hub I think there should also be a nether dungeon where you can fight nether mobs similarly to how the PvP arena might be made, it could be a way for islands to get beacons/1.16 items as well such as the warped and crimson nylium/wood/fungi etc.

It is a little buggy on bedrock but if you are using a touchscreen it’s slow  but it kinda works

There is one way of obtaining sand but that is from wandering traders, it takes a good 3ish hours for them to spawn and when they do you’d need to have found a way to gain emeralds to trade for the resource, so in the meantime I would recommend trying to generate some emeralds through villager trades