Although Mixit has the same line up as Player, Player doesn't allow for Personal Picks to be added. So they are separate tiers of service as far as I'm aware.
Same for Maxit and Full House - Maxit doesn't include the Kids channels, so is a separate tier even if the rest of the included channels are the same.
So it's possible to add a channel to Mixit but not Player (and above for legacy tiers) or in Maxit but not Full House.
Also there is no customer facing 'Reality tier' or singular 'Entertainment tier' in the Personal Picks -
https://www.virginmedia.com/content/...s_Feb_2022.pdf
The channels in 'Entertainment' are always linked to another set of channels. Excluding Kids.