Isn’t the solution to stream from your iphone or Mac to a solution like RooPlay (requires a Pi, and some configuration)? The kind Dr. is very active on these forums, and helps users with configuration and questions. This also gets you into the ecosystem where you can add his support for hardware volume controls etc. If you don’t want to build a pi yourself, I think he sells some sort of pre-built pre-configured branded version, tho I think it’s exactly the same as a fully DIY box. It can also run on some very lightweight Pi’s since current supply chain constraints are insane.
Forums;
Site with RooPlay and other extension content / where to buy: