Excellent point. I definitely was doing at at lower level crafts. After around level 25-30 or so, I just sorta, set up a macro, positioned the "Synthesis" directly above the macro on my hotbar, and clicked it every 30 seconds or so, and used the time to catch up on reading psychiatric medical journals, which I was going to do either way. Multi-tasking yo. If I set it up correctly, I'll still get the quality EXP bonus, without dividing my attention. Doing quick-synth and having to set it back up again every 99 synths I found to be a bit more distracting, as it would take me entirely out of my reading to set it up again (correct me if I'm wrong, but IIRC, 1 quicksynth takes about 3 seconds, which means a stack of 99 means I have to stop reading every 5 minutes to set it up again, which is too frequent a distraction for my tastes). Potentially useful for any students studying. Or not.
Then when I'm done reading, I just dump all the HQ mats into a guildleves, and craft up some HQ items with the NQ items and sell those.
Just like, for a Mythril Ingot, I'm looking at 2571 EXP for quick synth (with rested bonus), vs 7047 for a macro. Admittedly the macro takes about 10 times longer for 3x the exp, so it's about 1/3rd the exp-per-hour compared to just quicksything. But considering that 99 Mythril Ingots would cost about 3500*3+6500 = 17000g to craft, and I'd have to craft three times as many to get the same amount of EXP, it still comes out in my favor somewhat (Of course I could sell the Mythril Ingots for about 13000g per stack, meaning that if I only needed 99 Ingots, and just was quicksynthing for the same EXP, I'm only losing 8000g to get the same EXP in about 1/3rd the time if I sell the extra two stacks of 99 Ingots, which is a very reasonable and fair price). That being said, if I wanted to have to pay attention to my screen, a HQ Mythril Ingot guildleve would give a total of 86388+ ~11000EXP per craft = 97000 EXP per HQ ingot crafted. Which admittedly is slightly guildleve inefficiant, but insanely time-efficient compared to triple-turn-ins if you aren't suffering for a shortage of leves.
The best crafting/selling/leve choice is largely all situational depending on your degree of AFKness, and your desire for material, time, or leve allowance efficiency.
My apologies, I didn't mean to come off as rude. All dat edge is mostly me just doing it for fun. I find the optimization to be engaging and exciting; I'm quite well aware that most people don't draw the same level of enjoyment from systematizing. Ultimately I encourage people to play the way they find most fun as opposed to following the techniques of others to get a competitive edge. It's just a game, not the Olympics. My post was ultimately about curing misconceptions, not prescribing a correct way to play.
After all, just writing these posts on the forum cuts into my gil per hour, but it doesn't really matter because I find doing the analytical writeups to be fun!