eSIM and using an international SIM in a locked phone

Hello,

First time posting to a forum, so thanks in advance for any info.  

I have a iPhone 12 pro that has 8 more installments (AT&T) until fully paid and able to be unlocked.  It has a physical SIM card. 

My question is if I convert my physical SIM to an eSIM, would I be able to use an international (Sweden) physical SIM card in Sweden? 

My suspicion is that it would not be possible since the phone is still "locked." 

Any info would be great as I travel to Europe frequently and the data services through AT&T (when travelling to Europe) are much more expensive than local options.  It's too bad AT&T doesn't have a similar arrangement as they do in Central and South America.

Thanks,