players dont usually play minecraft without world generation mods, even with ExD installed.
they may find that their structures may generate or fail to generate unexpectedly.
sometime they need to find a another mod like Skyblock Builder.
since void world gen is builtin, why dont we make some enhancement?

well, SB mod provide several config files to configure feature & struct black/white list
for example, to generate some_mod:high_tower structure in a void world, just write config file "structures.json" like this
{
"structure": {
"white_list": true,
"list": [
"some_mod:high_tower"
]
}
}
as for the structure ids, SB will generate a structures.txt in $config_path/data as the first run, helping beginners to quick start

btw, Skyblock Builder is also a open source mod in github. Here is the link

What does "configurable" mean? Currently, the void generator allows configuration of which structures to generate through tags, and each Vanilla dimension can be enabled/disabled for void generation. End cities are patched to work with a void world.