Seems like a lot of work to make VoLTE work on your phone. I have a budget Chinese phone from like 5 years ago and all I did was type in a code on the caller part and instantly got VoLTE without any interaction with my carrier (Vodafone) or any downsides at all.
I guess if you have a closed shell case it’d be fine for the screen, but in my experience the screen is the only part likely to break and I’d rather not carry the extra size and weight of a case