Imperial Crusader BreastPlate rec. Spoil or Quest?

I asked many ppl, but noone was sure. Some told me that i need a quest... and its not so easy. But they did not remember any other details of the quest. Some others told me about spoil.
What it's true?

You should be able to obtain that recipe if you get to level 5 of ally with ketra or silenos.

not spoilable
you need a lvl 5 alligence with either ketra or varka

no s grade rec can be get by drop or spoil (only exception are shot and arrow rec)
they are all quest-only (like a grade was in previouc chronicle ....)

ok and lets say that I make ally lvl5 (up to now i have only in lvl2) and i get the recipe... may i have one more? Or if the recipe failed, what can i do to to take one more?

You need to hit lv 5, when you hit lv 3 you can get a side quest where you farm quest items who you buy the recipe from, you need like 1k per recipe.

800 for glove/boot/helm 2500 for mainpiece.

and when you hand em in there is a chance you just get adena - no rec