Yes, adding visual things are one of the ideas that will be done at some time. And you're right that storing entire worlds isn't worth the troube. :)
But as said, these worlds about I'm writing are more like super flat plots that are in the size of a .schematic file. Most people will probably only use it to create fancy trees, houses, jump'n'runs and other things, then save it like with .schematic to share it with others on Steem.
Bloat is not really an issue, as these worlds that I'm talking about aren't that big. My demo world, which has 4 chunks and over 260k blocks, with multiple armor stands that have custom heads has a size of 12kb. Many blog posts have more than that and bloat more than my demo world.
It is not really the idea behind this to save survival based worlds, but rather creative super flat worlds (in a small to moderate size) to Steem, that are not that heavy in size.
The idea is: I have made a jump and run and want to challenge other players to play my jump and run. Because of that, I built it using STEEM.CRAFT, which allows me to store the map to Steem. Other servers can then load the world from Steem to make it accessible to their users, which is important for me as an jump and run maker. Other users also can comment and vote on my jump and run map, this allows me getting direct feedback from other players that are not from the server I'm playing on.
For players, this is also nice, as they will get new jump and run maps directly from me, which they can play.
Having Steem here removes any middlemen and allows a direct save to and load from Steem without any external server. This means that the data can't be lost and my jump and run is safe from any server hardware failure that I'm not aware of, if I'm not the server operator myself.
Check into the structurize mod we made, we use some heavy compression to store .blueprint files (a format another dev developed). Might help you in this en-devour.
Thank you, I will look into it. :)
With sponge schematics v2, I'll get my 16mb demo world to just 12kb.