Why does the default reply within a thread use a different messaging mode?

For a saved contact, if a message is sent using an inreach ID the reply defaults to replying using a phone number instead of using the same messaging mode in which a message is sent. To reply to a message not using a phone number requires cresting a different thread to insure a message is sent to the inreach ID and not a phone number. This creates parallel messaging threads.

This is very inconvenient when sending and receiving messages. Can a solution be developed to ensure the same messaging mode is used for sending and replying to a contact to avoid creating multiple threads for the same conversation?