Morph formula field problem with length of field text

I searched for this, but did not see any directly related posts…
I am trying to type or paste a long formula into the morph field base on a function and find the field gets funked up when the text of the field gets beyond about 80 or so characters

I have tried to expanded the dialog box as much as I can, but while ‘I think’ text entry continues, it is not visible. In addition, as is shown in the attached picture the field seems to go into a ‘edit element icon’, seems to funk into a mode where it thinks I am editing some type of form or GUI element.

Is there a documented limit on these text fields? or is there a process to allow creating/editing a long value for these fields?
OSX 10.3.1


There is another way to fill a field with a formula.

It gives you a dialog like this.

The dialog can be expanded, if necessary.

There should not be any limit, but it does get awkward for super long entries.

As Dave pointed out, the Fill with Formula command makes it easier to work with longer formulas. However, I would also recommend making a temporary procedure and doing the fill that way, using the formulafill statement.

Thank you for the solutions!