Quick Synthesis failure rate (Deepgold Nuggest, Ingots, etc.)

Looking at my 70 BSM's stats and so on, it would appear that quick synthesis of, say, Deepgold (nuggets, ingots, etc.) should be fairly straightforward - (BSM stats, cft - 1775, ctl 1813, cp - 549; Matcha only) Nothing that I see in the Deepgold recipes indicates possibly poor quick synth success rate - but the failures are, well, nearly through the roof compared with SB stuff. The sense of it is that something has changed, possibly by way of definition? Anyone have an idea why, for what should be a pretty routine synth process, 7 out of 25 quick synth combines would fail? On behalf of the idea to change something to see if it makes a difference, I can't even begin to upgrade gear until level 74 - so, it is hard to imagine that gear is already an issue, which leaves the crafter with, essentially zero options? Doh. Missing something, big time.

Shooter

Food probably.

Popotoes au gratin from the CUL vendor in the crystarium gives CON +7%, CRAF +4% and helps cut my failure rate.

Have you tried at 71+?

ShB crafts are a little bit of a hurdle at 70. Meaning being below the recipe level, you have a big penalty to synth and quality increases. I'm not sure the exact reason, but this is far more pronounced at lv70 trying to craft anything 71+ than it would be at (example) 72 crafting a 74 recipe. Even Ingenuity doesn't cancel this out.

I can't say for definite this affects quick synthing, but it's likely.

I tried at 70. I didn't say I had no fails, just fewer with the vendor food.

At 70 Stonegold Nuggets went from about 1/3 fails to under 1/5.