My E-MU goes down to 2 samples, no problem. I only have experience with the ones I have.
I did a quick online class thing
on Jamkazam through the Jazz Education Network they recommend a cheap presonus audiobox 96.
Jamkazam allows you to play with other musicians remotely, latency is important, so a low buffer is of the essence. The UR-C series are just not able to do that because they’ve solved the “latency” with direct monitoring in the box. It’s good at what it does but you can’t do much else.