Nether Tweaks adds a couple of options for customizing Nether-related structures.
Fortress Height
Adds a configurable y-offset for Nether Fortress placement. You might want to do this if you have changed the height of the Nether or made more extensive changes to Nether worldgen.
Portal Restrictions
Allows you to disable lighting of Nether portals outside of the bounding box of a configurable list of structures. One possible use would be to only allow portals to be lit where a ruined portal already exists.
There is also an option to remove these restrictions once a portal has been successfully lit.
