Is there any way to make the answer be "yes"
MTAs and LDAs that don't support what the users want are thrown away.
Mailing list owners want per-recipient VERPs, for example. sendmail
doesn't support per-recipient VERPs. So they switch to qmail.
This is called competition. It's how the real world makes progress.
other than standardizing the format subaddresses?
It's none of your business how a host interprets its local addresses.
Set up a new mailing list in a single command. http://pobox.com/~djb/ezmlm.html