I think it’s less of an issue with mounting system as read-write and more of an issue with write_protect. The system mounts as read-write just fine even when write_protect is enabled, but some phones report that the setting has been disabled while it’s still active, so changes to the system don’t persist after a reboot. (I’ve had this issue with several T408DL’s.) The eitza would be to externally modify the system. Here’s how to do that with NeutronScott’s recovery2.img.
Guide to remove TCL Browser, Email, System Update, and CaptivePortalLogin using NeutronScott’s recovery2.img:
Please note that neither I nor anyone involved in creating this exploit can be held responsible for any harm it may cause to your phone, data, or warranty.
Proceed at your own risk!
First, see my TCL ROM Flashing Guide here.
After flashing vbmeta, vbmeta_system, and vbmeta_vendor and rebooting (step 9), run autobooter again. Once you’re in FASTBOOT mode, flash Neutron Scott’s recovery2.img to recovery with the command
fastboot flash recovery recovery2.img
and then reboot into recovery with
fastboot reboot recovery
IMPORTANT: If any text flashes on screen when you boot into recovery DO NOT run any commands from there. Reboot your phone (by tapping the power button while Reboot system now is highlighted), and then boot your phone into recovery again. You can also boot into recovery while holding the power and volume-up buttons while the phone is off.
Once you’re in recovery, run these ADB commands:
adb shell
su
lpp | sh
mount /dev/block/mapper/system /mnt/system
chmod a+rwx /mnt/system/system/app/Chromium
rm -r /mnt/system/system/app/Chromium
chmod a+rwx /mnt/system/system/app/PlatformCaptivePortalLogin
rm -r /mnt/system/system/app/PlatformCaptivePortalLogin
chmod a+rwx /mnt/system/system/priv-app/FPEmail
rm -r /mnt/system/system/priv-app/FPEmail
chmod a+rwx /mnt/system/system/priv-app/JrdFota
rm -r /mnt/system/system/priv-app/JrdFota
reboot
Iy”H, your Browser, Email, System Update, and CaptivePortalLogin should all be gone even if write_protect was giving you issues.