Hi @emalberi 

Welcome to the Sonos Community!

First of all, if you think the above is bad English, I envy you  Clearly, Italian schools are great!

On to your question. 

I really don’t know if there are matrix switchers out there that handle two ARC channels from both screens connected or not, but I suspect not - it seems the added complexity of doing so isn’t something these manufacturers are willing to include. A (quick) search produced no useful results.

The answer may be to not play services on the projector itself, but to instead use a streaming box of some kind (Apple TV, nVidia Shield, etc.) and use the Matrix’s “two way audio extraction” feature to play the audio from the streamer on the Arc - doing so may actually be cheaper than finding the golden-egg switch that will do it all (if one exists). This is assuming that the switch will reroute audio from an HDMI input to the eARC output of the switch, rather than just to the optical and 3.5mm outputs - I recommend being very sure of this before purchasing (or just be prepared to test and return if it is not performing as wished).

If you do upgrade your projector, I recommend a short-throw one - this will keep all your devices relatively close and negate the need for extra-long cables.

Having said all that, my posting here will get this topic back on the list of those that have been recently active - you may hear from someone with the device you are looking for yet.

I hope this helps.

Thank you for your answer and time spent to write! Yes sure it helps. Maybe someone else will answer with his experience or if I will decide to buy the matrix switch I will update the post for other persons interested in this.

@emalberi 

I just can agree to @Corry P and I‘m very sure there isn’t such a device available that supports all the features including ARC / eARC on two hdmi outputs. Some time ago I spoke to someone of „FeinTech“ here in Germany. They sell solutions like that, and he told me that there are technical limitations that prevent you from using two outputs with (e)ARC support this way. Probably there would be some signal conflicts. 
Imo the product in your second link currently is the best solution you can get. And the price seems quite fair I think. 

As Corry says I think you will struggle to find a switching device with dual eArc ports you can use for audio input. By design arc/eArc is not meant to be switched, split or combined, so the current devices basically de-embed the arc/earc audio from the TV for the analoge/digtal outputs and create a compatible signal with audio on the eArc port for the soundbar.

Even in the professional/commercial distribution products, they tend to favour inputs with audio routing rather than the complexities of multiple arc/earc connected devices.

The available consumer devices, including the more expensive hdfury devices, fit your current requirements of needing to connect sources to an eArc display, a non-earc display and an audio device which only has an hdmi eArc connector. They can also be used to deal with hdmi compatibility issues or providing uncompressed surround audio over hdmi to an avr without eArc.

For your future requirements, depending on the projector you buy, you may find the Android TV part of it is actually a HDMI stick with usb power, plugged into one of the hdmi ports in the projector rather than being actually built.

When I was looking at various switches and audio extractors while deciding what to do about my TV + Projector + Old AVR setup, many of the 4K Projectors I looked at that had Android/Google TV were using a hdmi stick, so not embedded into the main projector and could be unplugged from the projector and used in any device with a hdmi input socket.

In the end I bought I much bigger TV than originally intended, a complete new surround system + speakers and got rid of my projector. This was still cheaper and more usable than just the projector I was looking at and has none of the complications of audio + video routing a TV + Projector + eArc only audio device setup has.