Saxon

For the purpose of investigation, I have simplified the test case to

fold-right(-10 to 200_000, 1,  op('*'))

This is taking 2.59s with an upper bound of 100_000, or 11.24 seconds with an upper bound of 200_000 (measured using -repeat:10 on the XQuery command line)

I tried reimplementing fold-right($input, $zero, $f) as fold-left(reverse($input), $zero, function($x, $y){$f($y, $x)) but there is no discernible difference in performance.

False alarm. The fold is quadratic only because the cost of BigInteger multiplication increases with the size of the integers, and this calculation is generating some extremely large integers.