The Natural Philosopher wrote:

Went into Argos. Yes they had a
Huwaei P10 lite at a sane price. Went into Three yes
that phone would do wifi calling. Bought phone. Odd. No 'wifi calling'
on the menu.

Took it home. No wifi calling.

I did try to warn you that a sim on network X requires a phone bought
from network X in order to get notwork X's firmware, so that wifi
calling works.