1. That forge does not have any sort of "new metal standards".
2. That every mod that wants to define tin or bronze or ... does it slightly differently.
3. That there are still cases where the wrong mod's metal won't work.
4. That there is no default "unity" concept of the different-but-same metals.
5. That NEI can not display a generic "ore dict representation of X", but has to cycle through every type of X.
6. That NEI can not display all the recipes for all ore-dict compatible versions of X at the same time, but rather only displays the recipe for the specific version of X that you looked at ... ("tin gear", etc)
7. That NEI will list one thing on the right-side list of items (say, a resonant version of the induction smelter), and alter the ingredients in the recipe displayed, but suddenly they are NOT ore-dict compatible, and if you don't know this, and don't watch what you are doing, you are trying to make the parts for an advanced form of a machine block that you did not even realize, and went to all sorts of problems trying to make before you discover this.
GAARRR.
Yes, my first time making anything in forestry. GRR. Need invar to make an induction smelter. Need an induction smelter to make invar. GARRRR. Alloy smelter. Different types of that center block. Different types of gears. Different types of tin. Different types of bronze. GAARRRR.
EDIT:
1. What the heck is "invar" anyways?
2. Why require bronze, anyways?
3. Why "artificially" (at least, that's how it seems) restrict access to parts of the mod based on mod specific metals? At least Reika's steel makes sense.
1. Wikipedia: Invar, also known generically as FeNi36 (64FeNi in the US), is a nickel–iron alloy notable for its uniquely low coefficient of thermal expansion.
Ok, so an alloy extremely resistant to changes in shape/size from temperature. Fine. Why require a special furnace to make it normally?