J,
Yegads! I would have stopped you from going to all this trouble if I'd
known it was going to be complicated! I think I'll pass on this.
Thanks, I'll think about it.;)
The basic process isn't complicated, only step 4, the change itself, is actually needed.
If your members are basically savvy, and can be expected to understand an cope with the change in address by themselves then 3 and 4 together, warning and change, should suffice.
The rest is going "above and beyond" in mitigating the ramifications for the benefit of a membership of mixed or unknown level of understanding. It is a collection of ideas that have been discussed over the years in Y!GMF and Y!YGOG, gathered together and rewritten for Groups.io.
Shal
Shal Farley