try to remove all the preferred contacts in Android settings, and then set on of the SIMs as the preferred one. This way I think that the Android popup to select SIM should not be shown.
Then you use MTK Control entirely to select the SIM used to dial.
Please tell me if this helped.
Sorry for delay, did a full reset of phone to make sure no other apps messing with it.
No sim associations are set in android.
voice calls set to always use one sim
Rules created in MTK control to use second sim.
Phone will dial via Bluetooth speech recognition and appears to choose the sim but call ends without ever connecting. No box pops up asking for sim choice, interestlingly if the screen lock is off the calling screen doesn't show either.
I can hand dial a number and it appears to choose the sim and show calling screen but uses Bluetooth for voice.
Any other ideas?