My wife's 2014 XTS Onstar module will become obsolete with 2/3G phase out in Dec '22. I find threads detailing upgrades/swaps for same year (2014) CTS upgrades to 4g_LTE modules. Not finding similar onstar module swaps for XTS. I believe 2015+ model year Onstar module has LTE/Wifi. Has anyone successfully upgraded a 2014 XTS with the later module?