Update custom field at comment/reply/resolve time

RT 3.8.1

Our users have a custom field called “Quick Status” that they use as
part of a report for higher ups that just want a one line summary of
every ticket. Right now they work on something, go to
comment/reply/resolve it and update it, and then have to remember to go
back to the basics page and update the custom field.

I was going to add a Ticket Transaction Custom Field and write a scrip
so they can update the new CF and have RT automatically update the
Ticket level custom field, but I read that Transaction Custom Fields
aren’t available to scrips as of 3.6.1.

Is it possible to add a Ticket level custom field to the comment/reply
page? If so, can someone point me to an example?