There is an existing similar request that you are asked to attach last used email address to a contact but that seem pointless as I never open "Contacts".

My request is that the "From:" address change instantly to the email addresses used for the contact as soon as you select the contact in "To:" And that must be the ONLY email address that appears. You should show "Last used" at the top, and subsequently extend the list with others used and the last line must be "Show all addresses".

If someone sent me an email and changed their from address I would think they are trying to scan me even if the name is the same and this is a fundamental failure of the system.

New email creation should be
1. user starts new email
2. list all from: addresses
3. user types/selects to: address
4. system looks up history of to: address
5. system finds last used address
6. system changes from: and shows only last used
7. system looks for other from: address linked to "to:"
8. system shows clickable "list used addresses"
9. system shows clickable "list all addresses"

Of course, if this is the first time you send an email to a recipient then it just shows all with default at the top.

Simple. very simple and would make one not look like a scammer or an idiot.