I intentionally make amigurumi in blo for some of my projects. I think it's really cute, and although at first I was afraid that stuffing would show through the thinner fabric, it doesn't.

Seriously, there is no wrong or right with most things in crochet. If you like the look that's all that matters. Same with the "right side" or "wrong side" of amigurumi. It's personal preference! No rules.

The only issue I have with blo for amigurumi is I've found that spheres start to cone almost immediately, even though I'm increasing. Every time. I discovered if I make the first 6-7 rounds with both loops, then switch to blo, it works fine. Were you having any problem with your spheres coning? Like when making heads, I was making coneheads (not cute on SNL and even less cute with amigurumi).