In the limited amount of phone screens I’ve done this sounds like it would have helped.
The biggest problem with doing technical interviews over the phone is that when you ask hard questions, the subject of the interview has to think about their answer, and may even need to write things down to get their answer together. When you’re talking on the phone, nothing is conveyed. There’s an awkward silence punctuated by the interviewer letting the interviewee know that it’s OK that they’re not talking while they think about it. People get more nervous, and I think it hurts the quality of their answers.