How to enable subject line in iMessage on MacOS?

I would like to use the subject line on macOS when sending messages to my 'green bubble' friends since I'm using 'Text Message Forwarding' on my Mac and iPad. This helps me because when I add something to the subject line the message gets sent as an MMS instead of the crazy 1/5 2/5 4/5 3/5 5/5 broken up SMS messages that sometimes come out of order and without labels between certain cell carriers.

I use this when sending a message to ensure it gets sent as one message and not many since it sends as MMS. Also helpful when some smart punctuation autocorrect or emoji limited the SMS to 70 characters instead of 160. Try it, I dare you. 😃 Type in the subject and character count disappears. Or send it to a friend who is standing next to you if you have any 'green bubble' friends. (Character count is in the same area of settings as subject field)

IE: on iPhone > Settings > Messages > Show Subject Field.

IE: on iPhone > Settings > Messages > Character Count.

I've also sent feedback to Apple: Product Feedback - Apple about this just in case there is no method to do so. Or maybe this post will create more feedback submissions for those of us that have to deal with those green bubbles! As I know that not everyone deals with them that has an iPhone. Thanks in advance for your help or for submitting feedback to get the Mac as powerful as the iPad with Show Subject Line.