To have read-only for update requests when the column is locked, or only needs to be read (as opposed to being edited) would be a big help, and save lots of questions from recipients not knowing if they should change something or not. Plus, if conditional formatting could transfer across somehow to update requests (even with an asterisk or something) that would be great, so the updater could see if something is coming up to or past due date but status hasn't changed.
I very much agree - it would be great if locking the column made the field non-editable.
Similarly, it does not help that you cannot include placeholders in the subject or message fields, or else it simply sends the default text. I just created a ticket for this: https://community.smartsheet.com/discussion/120859/the-ability-to-use-placeholders-in-update-requests/p1?new=1.