Personally, I don't care about the thousands of phones that don't support eSim; that's on the manufacturers and those that buy them. All I know is that if I am going to a non-EU country, I don't have to worry about roaming because I can get an eSim for my phone for a few euro and get on with my trip.
All I know is that if I am going to a non-EU country, I don't have to worry about roaming because I can get an eSim for my phone for a few euro and get on with my trip.
Not so obvious as all that. He wants his customers to be able to ring him and message him on his usual number. Getting a local eSim won't help with that.
There's one other option I've thought of, but it's complicated. You could take out a subscription with a VOIP provider, who will give you an Irish number. You can set voice call forwarding from your mobile to this number, so calls from your clients will get delivered to the VOIP service. Typically you use a soft-client, ie an app on your phone to field such calls, and the app uses whatever data service you have.
So if you combine this with the 5g/wifi router option, you have a workable solution. You would have to weigh up all the costs involved, and look at the complexity and the likelihood of something not working smoothly against just taking a hit on the roaming charges.