Conversation mode - How to keep replied & Tr emails with change of subjects

Hi everyone,

I have been recently struggling with the conversation mode (that I love obviously). But one of my coworker is changing the subject of emails while replying or transferring emails which remove the actual answer of the conversation thread...

I have been unable to find a setting that allows all emails (that are a reply or a transfer) to stay in the same conversation even with a change of subject. Does it exist?

I guess this is actually based on the email subject so no, but dropping this here in case!

Thanks!