Who would you prefer to put Chaldea Lunchtime on?

Don't care about them and put it in your supports. If you are referring to Tama caster put it on her since she's your best support.

I also have no supports. I put it on my Ozy. He doesn't need a starting NP ce and since most Lunchtime CE will be on casters, I figure that putting it on a Rider will be at least different from the norm.

Riders are usually equipped with Mono Lisa CE so better avoid Chaldea Lunchtime on them.

Better put them on Caster as most people use the on Waver/Any other support, which happens to be Casters most of the time.

Tamamo, of course.

If you want it to be used by your friends, put it on a Caster.

Let me demonstrate why.

Of my 60 friends, at least 20 have it on a Caster, which means I don't even look at other classes.