Sponge-Forge does not create Lava Crystal Block of ArmorPlus Mod. I can find that block in single play world.(Default settings) I always check at a new world and same version mods&plugin, but I can find only single play. so I think it is sponge issue.
armorplus-1.11.2-9.5.4.5-beta.jar
spongeforge-1.11.2-2226-6.0.0-BETA-2114.jar
( Forge version is 2226 at client and server )