To the people who say "If they can pay for teams, they can pay for 16sc" or similar, again, fully understand and enterprise is more than acceptable for a requirement, but, we support over 100 clients with 90% being under 10 seats.
A lot of our clients are actually coming to ask and asking about using Teams more for every day requirements, or getting employees from other companies where they are using it, and to the every day end user, it works very well. The additional features, when you get head around it, aren't actually too bad.
I personally think 3CX is a much better platform, but, for ~£6 per user per month for Teams Phone licenses and then backing on to 3CX, it's a compromise to get the best of both worlds and I was hoping to embrace it a lot more.
My only fear is a lot of the smaller clients we planned to migrate to Teams Voice through 3CX won't have the budget for 16SC on top and we will be forced to go completely for Teams - then when they do grow bigger, there won't be a big enough reason to migrate away.
... Or, looking at the fact it costs an extra £495 per year per client (from 4SC), maybe look in to getting a different sip to teams proxy that can register as a sip client and can go to multiple teams tenants (last time I looked, this was about 4k).
It will just be a shame to remove such a promising feature out of reach.