Possibility to disable WiFi usage in Rainbow iOS and Android

Bacause of many complaints from customers (generally having consumer employees) about bad (Voice) connection thrue WiFi (especially clients on bad HomeWiFi) it would be a major solution to have a setting in the Rainbow app for choice between

WiFi-only  or  WiFi+4/5G  or  4/5G-only

Eliminating bad WiFi destroying an overall good working Rainbow app (iOS and Android)