Is a hand grinder enough for espresso?
Short answer: yes, if you make one or two drinks a day and don't mind a small arm workout. Long answer below, after five months of doing exactly that.
When I got the Gaggia Classic secondhand I didn't have money left for an electric espresso grinder that's actually good (the cheap ones are worse than a decent hand grinder at fine settings). So I tried the Comandante with the Red Clix axle, which gives you twice as many steps.
What works
The grind quality is genuinely fine for espresso. Shots are consistent enough that I can dial in a new bag in three or four attempts. With a medium roast I'm usually around 9–11 clicks on the Red Clix, 18 g in, 36–40 g out in 28–32 seconds.
What doesn't
It takes me about 50 seconds of grinding for 18 g of a light roast. Light roasts are hard beans and fine settings make it worse. On a weekend when two friends come over and everyone wants a flat white, it's a lot. I've started pre-grinding the second and third doses while the first shot runs, which is the opposite of what you're "supposed" to do but nobody has complained.
Changing between filter and espresso settings is also annoying: count the clicks back up, hope you didn't lose track. I keep a sticky note on the cupboard with both numbers.
If you're starting out and already own a good hand grinder, use it for a few months before spending money. You'll find out quickly whether espresso is something you'll do every day or whether the machine ends up as a very expensive shelf.