Sonos Arc would have perhaps been a better choice with a 55” TV as that has 11 drivers including two firing sideways and two firing up (Atmos), or you could have chosen a Sonos Beam or maybe a Sonos Amp with two floorstanders/bookshelf speakers etc; which provides a phantom center channel. 

All those could be used with two rear speaker surrounds, or another Amp/Speakers for the rear TV channel audio. 

All HT setups (and grouped rooms) can play music audio in either ‘ambient’ or ‘full’ mode in perfect sync.

If you go outside the Sonos HT setup and decide to ‘group’ two further speakers out in front, firstly they will only play a merged TV stereo image and secondly (importantly) you will likely see a 30-40ms delay to those grouped devices, which would cause an echo in the room for TV audio, but would play music audio without any sync issues. 

This is not unique to Sonos.  Every soundbar on the market has the front left, center, and right speakers in a single enclosure.  It's the very definition of a soundbar.

55 inch TV was my trial, mainly wanted to make sound stage wider.

I really like Sonos speakers sound character and simplicity, so i wanted to upgrade old Yamaha AV receiver with Eltax speakers in my living room cinema with 100 inch screen, but with current Sonos options it is really bad idea...

Ray even for 55 inch TV failed completely, It should really even be called as just stereo speaker with very narrow soundstage makes it absolutely useless for surround, it should be used as center only, there's no way it can be called 3.0!!  There is no chance to direct sound in this way! It will fail even for 20 inch screen !!! Ray as center only speaker would make sense but definitely not all in one 3.0.

I might get and try Beam gen 2 for my TV but again only single tweeter doesn't make sense, at least woofers are on the ends so it might help with sound stage.

Even with ARC is major fault, they failed to put tweeter in center how on earth any sound engineer would do that???

I have some sound engineering background in past, with designing and installing HI END car sound systems, and I know for 100% that sound stage is mostly built and directed with higher frequencies speakers and by mowing tweeter even feve centimetres sound stage can be really messed up. So all this Sonos surround sound concept is looking really wrong.

All soundbars are a compromise. If you are looking for a large front soundstage, unless you are willing to use the Amp solution, I would say Sonos is not for you.  In any case, I wouldn't purchase anything in hopes they will transform a soundbar into a center channel.  It's has been requested since the launch of the Playbar last decade, and hasn't happened yet.

The Ray is Sonos' lowest priced soundbar  i think is has been marketed along the lines of "improve your TV's sound". Expectations need to be reasonable. 

Exactly, but in reality it is making sound stage much narrower. So it makes it worse... It sounds like mono speaker...

Sony HT-A9 would do it but it is not a "Soundbar" as such.

Like I said, a compromise.  Fidelity  is increased at the cost of soundstage.  Lack of a wide soundstage from a 22" wide speaker should be obvious to a skilled audio expert.  You can only push physics so far.