The only way to accomplish your requirements is to use the Auto Attendant.
OBi200
Voice Services -> SP1 Service -> X_InboundCallRoute:
{+1222333444:aa},{ph}
Voice Services -> ObiBlueTooth 1 -> DigitMap:
(1xxxxxxxxxx|xxxxxxxxxx|xxxxxxx|xx.S3)
Voice Services -> ObiBlueTooth 1 -> InboundCallRoute:
ph,sp1(2223334444)
Physical Interfaces -> Line Port -> InboundCallRoute:
{222333444:aa},{ph}
Replace 2223334444 with your mobile GV number
Voice Services -> Auto Attendant -> Primary Line: OBiBlueTooth
Call the OBi200 GV number or landline number from your mobile GV app.
You can test to see which is more reliable.
You should get connected to the Auto Attendant
Select 1 to ring the OBi200 phone.
Select 2 to make a call from the paired mobile on the OBi200.
Inbound calls on the paired mobile will ring the OBi200 phone and your mobile GV app.
You will see the OBi200 GV CallerID on the GV app, not the original inbound CallerID.
I allowed 7, 10 and 11 digit outbound numbers on the paired mobile.
The "xx.S3" will allow any other numbers or add additional rules to the BT DigitMap.