This is a bit of a simple idea but I'll put it forward anyway. Why not when you enitrely clear an island (monsters, items, etc) you should get a small bit of EXP. Sort of like a pat on the back. Sorry if this has been suggested before, but I searched and could not find it.

Or like 200 Silver, or like 5 vermillion. Just something as a little "pat on the back" for clearing the island. Because I agree that can be hard!

I'd just be happy if they allowed us to just transport once enverything is gone/completed/defeated without having to walk all the way back to the portal.

I'd like the pat on the back reward plus the auto teleport. :D Maybe the auto-teleport could be an inexpensive to make scroll that lets you teleport out just by clicking it?

I feel like MollyOKami, I don't even need the extra reward (although of course it would be neat), but the need to walk all across the island again to teleport out is annoying so that would be great.

But Calib's idea sounds actually better to me! Use ink and something else to use up resources and craft teleport scrolls that you can use once per explore (and that are 1 use only), just like bandages.. 

I'd be happy with an auto-teleport personally.... I hate walking across an empty island :(