Best audio setting for 2.1 Soundbar + Kodi

Hi everyone !

I have some questions about my personal audio setting for Coreleec 9.2.2.
Sorry if I’m in the wrong category.
Before explanations about my problematic, let me precise that I’m not a fine connoisseur about audio or Kodi, so I’ll speak with my terms, trying to be as clear as possible (and so, I might say nonsense).

First of all, here is my current install :
My soundbar (which is Dolby and DTS certified) doesn’t allow anything else better than optical (no HDMI port), and my TV doesn’t seem to properly allow Dolby or DTS passthrough (after intensive researches here, rather common for TVs, when the audio isn’t coming from TV tuner)
I’m wondering about several things :
Should I let Kodi decode the sound, or would it be a best option to buy an HDMI switch with TOSLINK Out (bypassing the TV, and its apparent limitations) ?
If I understand correctly, there’s two different assumptions about that subject, which are the following (I’ll try tu summarize correctly) :

  1. 2.1 Soundbar, so even if it might receive and decode, let’s say Dolby 5.1 for example (assuming that S/PDIF limitations wouldn’t allow anything else than PCM 2.0 + Compressed multichannel Dolby or DTS), PCM 2.0 at the end, so it doesn’t matter if the decoding is done by Kodi or the soundbar, (same sound, same quality ?) ; that would imply that the simplest setting is the best, with everything set-up to the TV (I have some other devices, like gaming consoles).

And by opposition :

  1. Compressed Multichannel carries more informations about the discrete channels individually, offering a better distribution to the soundbar’s speakers (with intend levels and separation more respectful of what the content creator intended), with preserved Surround and LFE Channels ; that would imply that enabling passthrough in Kodi is useful, even in my case, and that a ~5-10€ HDMI switch with multiple HDMI inputs, and one HDMI output + one TOSLINK output might be a good purchase.

Could somebody help me, in order to identify correctly the best configuration ?
Any advice would be gladly appreciated, thanks.