Its a dynamic assignment and we should stick with that approach. Is there a specific use case here ?
so the use case is that we want to map VLAN with the VNI on physical switches. for example, vlan 10 maps to VNI 10010 and vlan 20 maps to VNI 10020. and VNI should be same as Segment ID. so if we can give static segment id it will become easy to identify which vni is maps with which vlan id.