Homunculus Servant = distance touch spells on a PC at any point?

My question is that since the HM is a tiny creature (not 100% on that) is it unreasonable for it to sit on a PC shoulder or something similar and use its feature Channel Magic to cast a touch spell (for example cure wound) at any time because the HM is always touching the PC?

Also a bit unrelated but since Mending is a touch spell and the HM can heal from it (also not sure about that) Can it use Channel Magic and me cast mending to heal it from a distance?

I think the idea is to have the Homunculus Servant (HS) sit on an ally's shoulder (not your own) allowing you to cast healing/support spells with a range of touch on that ally up to 120 feet away.

For example healing a Barbarian with cure wounds without having to risk getting in melee range yourself.

This works but do note this puts the HS at risk of being attacked alongside the ally it's riding upon, granted an attack on the HS is an attack your ally isn't taking.

Thanks for clearing it up, I was asking because the characters in the campaign I’m about to play are mostly front liners and we don’t actually have anyone with like healing word or other buff spells.