I’m very happy for you 🙂 I miss working on the field 🙂
So basically, you should see 2 scenarios:
1/ In loaded cells, calls are setup in HR. If the call is MS to MS, then the distant MS will be downgraded to HR (if distant cell allows it) and TFO will be ON.
2/ In non loaded cells, MS-MS calls, both MS should be in EFR.
After HO, if one MS goes to HR, the distant MS shall be downgraded to HR.
During your drivetests, you should ensure that HR-HR calls with TFO have better voice quality than without (this, you must check by listening to the mobile phone DURING the drivetest… SQI is not so reliable)
Don’t forget that MS-Fixed line will not use TFO 🙂