flighty_sloth
Hi,
yes, there is an indicator for SIM #1 and SIM #2.
As I remember, it is not a strict separate message thread per SIM.
If not directly, then after long press on a thread and then tap on the (i) top right.
Unfortunately I can not describe it more exactly, because I don't use Dual (e)SIM any longer.
But other users can look at their SMS app and describe it more precise. ;-)