An alchemist that good would probably be more than C1. It doesn't invalid your point though.
One of the big issues I think is that you must know something is coming and when. Is some runs (like B&E, extractions or maybe even wetwork), it's no big deal: you make the schedule.
But in some cases (mostly when you play defence), you don't know the schedule, you have no way to know when something will be going down. And you can't keep preparing potions and spending reagents (1400 nuyens for your potions, best not waste too much if you want to earn anything in the run. Even if you can find some of the reagents by yourself, given your consumption you'd need quite a bit of downtime to find the quantity you use.). And then...you're screwed. Not useless, you still have some stuff you can do, but the thing your alchemy will be.
I didn't need to use Reagents for as many Preparations as I did, but it does save a little bit of time. You're going to end up having more Stun Damage to heal in between making Preparations. Probably saved only a couple hours using Reagents.
I tried making Preparations using No Reagents, actually was way better than I thought. Only had to remake One Preparation, and didn't have to spend any Edge.
[spoiler]
Start at 00:00 Increase Reflexes (Force 7), 6 Drain
Rest 1 Hour, Heal 5 Stun
Increase Agility (Force 7), 1 Drain
Increase Reaction (Force 7), No Drain
Combat Sense (Force 7), 3 Drain
Rest 1 Hour, Heal 4 Stun
Deflection (Force 7), Potency 3, 4 Drain Rest 1 Hour, Heal All Stun
Remake Deflection (Force 7), 3 Drain
Stealth (Force 7), 3 Drain
Rest 1 Hour, Heal 4 Stun
Improved Invisibility (Force 7), 5 Drain
Rest 1 Hour, Heal 6 Stun
Detect Life (Force 7), 1 Drain
Detect Life (Force 7), No Drain
Heal (Force 5), No Drain
Heal (Force 5), No Drain
Heal (Force 5), No Drain
Heal (Force 5), No Drain
Levitate (Force 3), No Drain
Levitate (Force 3), No Drain
Levitate (Force 3), No Drain
Levitate (Force 3), 1 Drain
Rest 1 Hour, Heal All Stun
End at 6:42 PREPARATION FORCE POTENCY FINISHED AT: FULL POT TILL:
Inc. Reflexes 7 6 0:07 12:07
Inc. Agility 7 7 1:14 15:14
Inc. Reaction 7 7 1:21 15:21
Combat Sense 7 7 1:28 15:28
Deflection 7 7 3:42 17:42
Stealth 7 6 3:49 15:49
Improved Invis 7 7 4:56 18:56
Detect Life 7 4 5:03 13:03
Detect Life 7 5 5:10 15:10
Heal 5 5 5:15 15:15
Heal 5 5 5:20 15:20
Heal 5 5 5:25 15:25
Heal 5 5 5:30 15:30
Levitate 3 3 5:33 11:33
Levitate 3 3 5:36 11:36
Levitate 3 3 5:39 11:39
Levitate 3 3 5:42 11:42
[/spoiler]
And this is what I rolled for using Preparation (Force + Potency)
Increase Reflexes (8 Hits, Limit 7)
Increase Agility (4 Hits)
Increase Reaction (3 Hits)
Combat Sense (9 Hits, Limit 7)
Deflection (7 Hits)
Stealth (5 Hits)
Improved Invisibility (4 Hits)
Character Temporary Stats. Agility: 7
Reaction: 6
Initiative: 18 + 4D6
25 Dice Against Ranged Attacks
18 Dice Against Melee Attacks
Intuition + Logic (4) for any chance to See Character
Intuition + Logic (5) for any chance to Hear Character