We're glad you asked! Roaming can be confusing, and it's definitely a setting you don't want to mess up (unless you're a fan of paying extremely high, unpredictable carrier bills after a trip).
When you're using aloSIM, your eSIM should have roaming "ON."
That's because you want aloSIM to make sure you're connected to great local networks wherever you're traveling. This is just how your device understands that aloSIM might be switching you from one network to another in order to deliver the best possible connection. You won't be charged anything extra, of course.
If you have a Primary SIM, roaming on that should be "OFF" while you're using aloSIM.
This is because you do NOT want to be relying on your Primary SIM (regular phone number) when you're traveling outside of their coverage zone. You want to rely on aloSIM only.
Many, many travelers have gotten into trouble by accidentally turning roaming on for their main SIMs, and their phone carrier back at home has eagerly tracked each and every second of international data usage. So absolutely, positively, keep roaming "OFF" whenever you leave your usual coverage area.
When you're using aloSIM, you want us to take care of your data needs -- not your regular carrier. When data roaming is set to "OFF," you're telling your carrier back home "Nope, please don't try to connect me to your expensive faraway networks. aloSIM is doing that instead. I'm fine, thanks."
And the best part? You won't return home to any roaming charges on your next bill. Yay!
So, just to re-cap:
Your aloSIM eSIM = roaming ON
Your regular SIM (if you have one) = roaming OFF