Bulk Assigning Contacts to Specific Lines for Dual Sim Setup or Dual Phone Line Setup International Use Case

I've read in a few place of people still having issues with the multiple sim setups where the contacts are assigned to various sims without a methodology to bulk edit preferences or create smart rules for which line is used in any given situation.

Dual sim setups are not intelligent enough to associate international numbers with their respective esim or sim. So I have a sim for the UAE and one for North America but the contacts are all confused regarding which line should be used to contact each various set of contacts. It is easy to make a smart list in macOS contacts by country code so they are grouped, but then assigning an entire group to a line seems missing.

Even worse, I've dealt with various international lines for decades by using my iCloud email for iMessage, but the new sim assignments seem to default iMessages back to a specific line based on the contact preferences even when all new iMessages are meant to be started from my iCloud email address. This seems to be a bug.

It would be super handy from the international perspective to auto set the default line to the one with the matching country code. Then to also respect the default iMessage address...

It doesn't feel like the use case of international sim cards/lines was really considered vs. the use case of home/work lines in the context of contact assignments and dual sim setups.