SNAT with client and pool member on same subnet

You could use it in the LB_Selected event and the LB:erver event

https://clouddocs.f5.com/api/irules/LB__server.html

https://clouddocs.f5.com/api/irules/snat.html

there is a good starting point iRule that is liek this:

# Apply SNAT automap for clients in the 10.10.10.0/24 subnet
when CLIENT_ACCEPTED {
   if { [IP::addr [IP::local_addr] equals 10.10.10.0/24] }{
      snat automap
   }
}

And looking here for the iRule event order - it shows it should work https://clouddocs.f5.com/training/community/irules/html/class1/module1/iRuleEventsFlowHTTPS.html