Not sure if this helps but I use a Smasung A50 with libre2+ , which is not on Libre list of compatibility but it does work IF you don't mind the Bluetooth gobbling loads of battery and internet/WiFi. So much so that I have to keep turning Bluetooth off and on to use virtually any other app on my phone. That, however means losing alarms when Bluetooth is off. Not at all ideal for T1s.
So maybe, before committing to new phone try it on what you've got, see if it does work? Is that possible? (I'm not very techy, sorry)