Courtesy Callback Handoff error

I have been working on CCB for a while now. Everything seems to be working properly but if I increase the EWT for CCB to more then 60 mins I get handoff error in the VXML gateway and Callback_wait. I think it's because there is too many loops in the callback_wait application.

My question is : The error is it coming from CVP or VXML and is it possible to permit a longer wait time in CCB. My ideal would be 120 mins. Meaning I would allow customer to request callback if the estimated wait time is less then 90 mins. But with the multiple attempt (busy, No Answer, etc...) I would need the Callback_Wait to be able to last up to 120 minutes.

Handoff error can be because of the maximum number of handoffs (i.e.100) is reached. 100 is hardcoded in IOS-GW code. You can still manage 90m>EWT>60m. We have recently tested for around 80m and we didn't see handoff failures. But If we go close to 90m, we start seeing the issue.

Thanks