While I fully approve not using your phone, the company should issue you one, what is the security benefit of not using a personal phone? It's not really different from a company phone.
You can treat a company phone as adversarial (e.g. leaving it at home or on airplane mode) without impacting your normal life. An MDM solution can usually get real-time location information, not to mention potentially access other personal information. And your real number should not be associated with work things as a matter of course, in my opinion.