Apple Watch - Family stand alone device limitations?

So as every parent knows the sooner the little buggers get access to a smartphone the sooner their little brains turn to mush :) So an Apple Watch seems to postpone the inevitable. So two newish cellular 6 Apple Watches from backMarket were duly deliver by Santa (cellular plan for pre paid T-Mobile US accounts via TruPhon in UK :) !!!) and now they are texting their pals and seem to love the new ability to contact them even 30s with some mindless banter.

But there are some limitation to a watch not linked directly to a phone:

  1. No whatsAPP - not a bad thing but their less evolved android pals may be left out in the cold
  2. No group voice chat - may be a blessing in disguise
  3. No wifi calling
  4. adding contacts is a pain even sending a vCard - did try to log into iCloud.com and add stuff to address book but did not seem to sync quickly
  5. iMessage group creation on watch - not sure how to do this - I created a group on MacBookPro.

I realize that the apple watch was created to be used with an iPhone but of course in this case the phone is MIA but obviously there is some functionality baked in as apple created the Family watch thing. Of course the little darlings will eventually get a phone so this is just a temporary issue for a few years or more. They do have access to iPads and a laptop so that’s an option.

What other limitation should we be aware of and perhaps there are some tricks around them - using Siri more ???