Just pre ordered the Unlocked Galaxy S21 Ultra 256GB from Samsung taking advantage of the great amazing pre order deals. Will get it on Feb 29th estimated.
I currently have the OnePlus 7T that was supposed to be incompatible when it first came out. Yet that worked without any issues on day 1.
So, taking a risk hoping it will work no problem with switching SIM with Visible. At least sometimes in February. Will come back here and give you guys and update once I try.
Update: Feb 2021, Works on Visible just fine right out of the box. WiFi Calling and WiFi Texting also works.
http://19216881.onl
http://jiofilocalhtml.co.in
http://router-network.com