Yes, the Meander WiFi models can be fitted with an analog or digital input upon request. The Twist WiFi has these inputs as standard. This can be connected to the output of the Sonos Port. Also, the WiSA SoundSend can connect the WiSA models through its optical input to the Sonos Port. If you want the powered Davone speaker volume to change together with the Sonos speakers, you will have to set the output level of the Sonos Port digital output to variable. The relative volume of the Sonos and Davone WiSA speakers can be set in the SoundSend app. The WiFI models can be adjusted with the optional remote control. The passive Davone speakers can be connected directly to the Sonos Amp.
No. Even though WiSA is a audio standard used by manu audio manufacturers, the B&O transmitters are not WiSA compatible. The B&O loudspeakers are WiSA compatible. This means that it is possible to connect B&O loudspeakers to a LG TV with build in WiSA, but it is not possible to connect WiSA loudspeakers to a B&O TV.
No. Changing the volume level of a digital output reduces resolution. But if the processing is done at 24 or more bits, which it usually is, the sound level can be reduced with 48db (which is a lot) or more and still retain 16 bits cd-quality resolution. So in practise it is no problem to use a variable digital output. In general the recording quality is far less then what the rsolution would allow.
It is sometimes reported that the digital outputs on cheaper devices might include limiters or other processing which might degrade the sound quality at higher levels.
No. WiSA basically replaces the loudspeaker cable. It is not connected to the internet. It creates its own closed network with the WiSA transmitter and receiver. Once it is set up it will remain working and no updates are needed. Only when a transmitter is chosen with build in WiFi as music source, can the transmitter become outdated. But those devices typically have Over The Air (OTA) updates to keep your device up to date wit the latest version of Google Chromecast for example. The Meander works that way.
Streaming music over WiFi requires a WiFI music streamer like the Bluesound Node. It downloads music data in real time from the internet and plays it back over an output that is connected to your amplifier and loudspeakers. There are also complete music systems that have such a WiFi streamer and amplifer and loudspeakers build in. This works great for stereo from a single device, like the Meander All-in-One. Getting stereo from 2 seperate devices requires the music signal to be synchronized between the 2 devices. Brands like Sonos, Bluesound and Heos offer this option, but the stereo quality is low because the synchronization requires constant adjusting of the left and right channel delays, causing a drifting stereo image. This is where WiSA comes in. With a inaudible low and stable latency between up to 9 channels, the stereo and multichannel imaging is perfect. WiSA is basically a wireless replacement of a speaker cable. And just like a speaker cable it can not download music from the internet. It needs a WiFI music streamer like the Bluesound Node to connect as source to the WiSA transmitter. An alternative solution to the WiFi synchronization limitation between seperate devices, is using a classic loudspeaker cable between the two and use only one WiFi receiver. Davone offers this option for the Meander and Twist WiFi stereo pair.
Bluetooth is a wireless technique that replaces a wire. So it is the same as WiSA you say. No, not at all. Bluetooth was originally designed to consume only very little power. It has a relatively simple handshake between devices (the pairing) compared to WiFI / internet communication. Bleutooth is therefore very popular for controlling devices using simple commands. If you use an App to control a device in your home it is very likely using Bluetooth (the first contact Chromecast makes to connect the Davone WiFi speakers to your WiFI is also over Bluetooth). Clearly, Bluetooth was not intended for high quality music streaming, although it is also getting better with time. WiSA by comparison, is designed specifically for high quality multichannel music streaming.
The main drawback for using Bluetooth for music streaming from your mobile however, is that your mobile is the streaming source and your battery is drained while you listen. Chromecast and Airplay 2 is software (they are not a wireless connection like Bluetooth or WiSA, they use the existing WiFi) that enables music streaming directly from your router to your WiFi audio system or loudspeakers. Your mobile only acts as a remote to control what you stream etc. There is no power limitation, so high resolution music streaming which means large data downloads, are no problem. The only drawback is stereo reproduction from multiple devices is of limited quality. This is where WiSA is excellent.
So as it stands today, there is no technique that can do it all. Which technique you should use depends on what you want to achieve.