Current 4K + 120Hz + eARC + CEC setup

I'm looking for some help adding Hyperion to my entertainment setup. I have a 4K 120Hz TV paired with a soundbar connected through eARC. With that I have a PC, Nintendo Switch, and will possibly add a Chromecast. I use CEC for some devices, but when it's not available I've been able to bridge the gap using Home Assistant. I've been interested in adding ambient lighting to this setup for awhile but each time I consider buying hardware I have a difficult time finding something that would maintain the current features I enjoy. I don't really even understand how my eARC soundbar effects this, but looking through the forums it is something mentioned by others. Does anyone have recommendations or ideas on where to go with this?

Thank you for the resources and clearing up my confusion about eARC! Will a grabber that scales to 1920x1080 60Hz result in any picture quality loss?

It also looks like there is only one splitter (HDFury – Diva -Matrix Switch 4x3) that supports HDR. If a splitter does not support HDR, then will my video content not be HDR?

I think I may be confused about how this hardware effects my TV image. When colors are washed-out, does that refer to the colors of the LEDS behind the TV, or the colors the TV produces. Does any of this additional hardware change the image quality and refresh rate of my TV? I've been looking for devices that match the specifications of my TV because that was my main concern. If lesser hardware results in a less snappy, less colorful ambient lighting I can live with that.

I've been down the rabbit hole and I'm starting to get an idea of how this comes together (I think).

I'm considering picking up something like this 4K 120Hz HDMI 2.1 Splitter from EZCOO. The splitter device is responsible for the image I see on the TV, therefore this is what needs to be compatible with 4K resolution, 120Hz refresh rates, CEC, viewing DRM content, Dolby vision, etc.

The grabber (or capture card) does not require any of this. If it is only 1080p 30hz it will not change the image I see on the TV. It simply grabs the image on the TV to mirror colors in the program which tells the lights what color to be. I'm considering this grabber.

Am I on the right track with this? Thank you for the support.