How to use modulo operator in Terraform CDKTF without escape hatch?

I am trying to use % to test out a scenario where I need to parse the value to integer and get the remainder.

this._zones.names is a DataAWSAvailabilityZones All, so contains a list of three elements (zones)`

My code.

     tags: {
        Zone: Fn.element(this._zones.names, (Fn.parseInt("4", 10) % 3)),

If I am correct, the above correct should return the index at 1 and spit out us-east-2b but it always resolves to zero.

When I run synth however, it completely ignores the % modulo operator, and outputs the following in my cdktf.json file for that stack.

     "Zone": "${element(data.aws_availability_zones.all.names, 0)}"

I can use escape hatch but thought I could use operators?

CDKTF v0.14 has introduced the Op class which we can use.
For eg. Op.sub(5, 3) , Op.div(length(list), 2)