Newbie Q about UltraStudio 4k Mini to Sony OLED TV

Hi all, I'm fairly new to Davinci Resolve Pro but with a soon to come move I want to upgrade my editing/colour correction options and I am a little confused as to which solution I need and hope for some friendly advice for a newbie wanting to get the right things the first time

My goal is to use our coming "movie room & home office" space to use a Sony 77" OLED XR-77A80K ( sony.com/electronics/support/televisions-projectors-oled-tvs-android-/xr-77a80k/specifications) as the client review & colour correction & grading screen.

In order to use the Sony TV as a separate monitor/screen, I can obviously connect it via an HDMI cable straight from the MacBook Pro but I understand this is then affecting the video output by whatever macOS wants to do or is set to, and that the more "correct way" to do it is to use something like the Blackmagic Design UltraStudio 4K Mini - is that the right assumption? I understand there are much simpler, smaller devices (HDMI Monitor 3G) but those would not output 4K as far as I understand. I really appreciate the feedback so thanks in advance.

Here's the gear otherwise available/I use in case it matters to any of this:

Software: Davinci Resolve Studio
Hardware:
- MacBook Pro M1 Pro (soon M3 Pro or Max?)
- recording on Panasonic EVA-1 (using Atomos NINJA V) and Canon R6 Mark 2

Thanks & best regards from Sweden,
Jonas

That should be the right I/O device for monitoring in 4K, or, actually UHD, which that screen supports. If you want to work for the movie industry, you have to be aware that it's not really 4K.
As we say here "the devil is in the detail". Another detail is occasional incompatibility between HDMI devices, and unfortunately, that screen doesn't have SDI. So, contact BM if they know or make sure that you can send the I/O box back in case it doesn't talk to that screen.
Hopefully, somebody who owns the pair will comment.

Vielen Dank Uli - helpful tips indeed!
I understand this might not be the ideal option for grading it and that a separate monitor for this would be better. Looking around the Atomos website for some information on my Ninja V i saw the Atomos SUMO 19SE - would this be an acceptable compromise without shelling out 40' USD on a "real" monitor? Because I see some pretty useful extra use for that if it would be OK.

Sorry, I have no experience with that Atomos device. You're aware that it's HD only and that you'll need a Calibrate for it to get precise colors?
Its advantage is the SDI input, which shouldn't have any compatibility issues. It'll down convert for the screen.