Javascript / Googlescript using set.Formula with complex formulas - multidimensional-array

Question

I have researching this but cannot find a suitable solution. The following formula works fine at the formula level when placed in a sheet cell. The issue is I want the formula to run at the script level. The options I am aware of include running a script to:
(1) set.Formula('=complex formula')
or
(2) rewriting the entire formula as a script
I am new to GAS, and have messed around with both methods. There seems to be a syntax error when using option (1), usually in the form of a missing ")" that I cannot debug. Employing option (2) is currently above my skill level. Any help on either option would be greatly appreciated.
Here is the formula in question:
=ARRAYFORMULA(QUERY({UI!A:G,YEAR(UI!A:A),MONTH(UI!A:A), TEXT(UI!A:A, "MMMM"), TEXT(UI!A:A, "MMM-YY"), REPLACE(UI!A:A,1,1000,"GRAND
TOTAL")}, "SELECT * WHERE Col1 IS NOT NULL AND Col2 IS NOT NULL LABEL
Col8 'Year',Col9 'MonthMO#',Col10 'MonthMO',Col11 'MonthMOYR',Col12
'GRAND TOTAL'"))

Answer 1

Answer
Formulas doesn't run "at script level" so you will have to rewrite your formula as a Google Apps Script / JavaScript function.
Escaping formula apostrophes in scripts
In case that you want a script to add your complex formula to a cell bear in mind that writing complex formulas in one line makes harder to debug them.
Try dividing your formula by functions and parameters and use a tab to align them. IMHO this prevents that the use of \ makes the script unreadable (Leaning toothpick syndrome).
Below is a onEdit() function that inserts the complex formula in the question to the cell to the right of a cell where 'Yes' is wrote. Look to the use of \ to escape the apostrophes used in the second parameter of the query function (select statement).
function onEdit() {
var ss = SpreadsheetApp.getActive();
var rng = ss.getActiveRange();
var trg = rng.offset(0, 1);
var formula =
'=ARRAYFORMULA('
+ 'QUERY({'
+ 'UI!A:G,YEAR(UI!A:A),MONTH(UI!A:A),'
+ 'TEXT(UI!A:A, "MMMM"), '
+ 'TEXT(UI!A:A, "MMM-YY"), '
+ 'REPLACE(UI!A:A,1,1000,"GRAND TOTAL")'
+ '},'
+ '"SELECT * WHERE Col1 IS NOT NULL AND Col2 IS NOT NULL LABEL Col8 \'Year\', '
+ 'Col9 \'MonthMO#\', Col10 \'MonthMO\', Col11 \'MonthMOYR\', '
+ 'Col12 \'GRAND TOTAL\'"'
+ ')'
+ ')';
if(rng.getValue() == 'Yes') trg.setFormula(formula);
}