I think this thread came to the right conclusion in the end, but here's what I found on the subject, thought it might help if anyone else is searching for the same question.
From what I've found through various searches suggests that it's not only the disc drive itself that allows you to play 4K UHD content, but the ability of your CPU to decode the DRM on 4K UHD discs.
Here some links to system requirements:
Get information on the LG WH16NS60. Find pictures, reviews, and tech specs for the LG WH16NS60 Internal Blu-ray Drive Ultra HD Blu-Ray Playback & M-DISC™ Support
www.lg.com
The common factor is the requirement for Intel SGX so if you're Team Red you seem to be out of luck. (Regular FHD Blu Ray should be fine though)
A couple of links to discussions on the topic:
Greetings, In order for the new 4k Blu Ray drives to work, the CPU needs a special instruction set. This instruction set has been available on 7th gen
community.amd.com
Hi, Everybody I just built my 1st pc and I went with a ryzen 7 3700x CPU, asus dual rtx geforce 2080 0C GPU, asus tuf x570 motherboard, 2x 8gb 3200 ddr4 ram, M2 ssd, and a Pioneer 4k UHD blu ray. To my dismay after all my reserch to build my pc I found out that AMD does not support SGX PSW, Ive e...
linustechtips.com
Looking for a Blu Ray drive specifically for the NCase (slot-loading) I didn't come across any that specifically mentioned UHD and most were discontinued though still available on sites such as ebay. Here's a list of Slot load Blu-Ray drives that I've come across:
LG
CA40N (Read Only)(Discontinued)
CA30P (Read Only)(Discontinued)
CA10N (Read Only)(Discontinued)
TEAC
BD-C16SS-A90 (Read Only)(Discontinued)
BD-W26SS-B (BD-R TL/QL)
Panasonic
UJ167 (Read Only)(Discontinued)
UJ235 (Discontinued)
UJ265 (BD-R TL/QL)(Discontinued)
UJ267 (BD-R TL/QL)(Discontinued)
Sony
BC-5600S (Read Only)(Discontinued)
BD-5640H (Discontinued)
BD-5841H (Discontinued)
BD-5850H (Discontinued)
Streacom
OB1 (Read Only)(Discontinued)
OB2 (Read Only)(Discontinued)
OB3 (Discontinued)
I was wondering if drives that were capable of reading BDXL (BD-R TL/QL) would be able to read 4K UHD, (assuming the rest of your hardware was compatible) but it seems that's not the case from what I read here,
Can BDXL compatible PC recorders read 4K UHD Blu-ray? Blu-ray PCs, Laptops, Drives, Media and Software
forum.blu-ray.com
But that doesn't do much explaining, so I haven't ruled it out completely.
It seems that at least for now the NCase is limited to FHD internal Blu Ray disc drives by the hardware available. And the only way to play 4K UHD content is to download, or rip and then use software.
I did all this searching as research for my first build so I am by no means an expert in the subject so If anyone can offer further insights that'd be appreciated.
TL;DR:
There are no internal UHD 4K capable slot loading drives on the market (That I've come across) and if there was you would need to be running an intel system <7th Gen CPU on a MOBO with support for Intel SGX in order for it to work.
