Parsing a huge json body in a groovy step

I have a REST request that returns a HUGE json body, 3.6+M bytes, 76+K lines,

that I need to validate.  I'm using a separate groovy step to do the validation.

The request responds fine and I see the results.

The groovy step can get the response OK too with

testRunner.testCase.getTestStepByName("stepName").httpRequest.response.responseContent

But when it tries to parse the json body with JsonSlurper(),

SoapUI completely locks up forever.

I have to kill the soapui process in the Task Mgr and restart soapui.

So it effectively can't parse this large response to be able to validate it.

I've looked online and here at SB and soapui preferences but don't see any info on this.

Is there any way to handle these large json bodies?

I'm using SoapUI OS on a Windows 10 PC.

Can ReadyAPI, SoapUI-Pro, handle large json bodies better?

Thanks.