I mean, you could use the private DNS feature instead of AdAway. No need of root for that. If you want to keep root anyway, IIRC there's a project called kernelSU, which being "in kernel" is probably less detectable than Magisk. Keep into account that - you would need to unlock your bootloader anyway, which sometimes can be a big "no" for bank apps
- I don't know if the project is still active.
- Someone has to have compiled a specific kernel for your device, with the requested patch, or you have to do it yourself.
I apologize if something is not exact, it's been a long time since I have looked into it.