I don't know, if this is an issue with TiCon or ModTweaker, but a recipe, such as

mods.tconstruct.Smeltery.addMelting(<ore:sandstone>, <liquid:glass.molten> * 384, 800, <minecraft:sandstone>);

will not make any sandstone melt.

I'll try to compile it and check it out, see if it works now.
Is there a planned release coming sometime soon?

I vaguely remember fixing this. If not, just open it back up

Once TiC support is fixed I'll look if it works

TiC support is supposedly fixed now...just waiting for the fix to be released.