Thanks for your feedback.
Yes it special request for this to work on in such a way.
I did on what you mentioned on the DMZ interface create the MIP as below
MAPPED IP is 10.1.1.250
Host IP is = 192.168.1.10
MASK = 255.255.255.255
On the policy level just for testing purposes. I allow "ANY ANY" from DMZ to TRUST & TRUST to DMZ "ANY ANY".
I still NOT able to ping 10.1.1.250 NATTED IP from my DMZ network.
On contrast and weirdness
I created MIP on Trust interface
MAPPED IP is 10.1.1.250
Host IP is = 192.168.1.10
MASK = 255.255.255.255
Policy level same for testing purposes "ANY ANY" from DMZ to TRUST & TRUST to DMZ "ANY ANY".
I CAN to ping 10.1.1.250 NATTED IP from TRUST network.
BTW my DMZ interface is routed mode & my TRUST interface is NAT mode not sure if it make any difference.