String expression control

I reiterate my request for a string expression control. String manipulation is an entirely separate concern than text styling. My last post got merged into "text expression control" thread.  I try to build very lightweight deliverables and I am striving to eliminate the need for say, hidden text layers. While JSON or JSX is an interesting workflow for the more development oriented people, it's not really editable by the end user. I do not necessarily utilize EGP in my work. My idea is simply an expression control like a checkbox, slider, color well etc but containing simple a text field.

Certainly it's doable, I'm sure there should be a limit, what if a user 3 years from now posts an entire copy of Moby Dick into one of those... but if the cap is even something terse like 4096 characters, it would make my life easier, and there's precedent for how it should work without designing new UI.