NightBreeze

I would say @SS_Dave's comment is very accurate. The main benefit of using the Noctua fan is noise reduction and increased lifespan (potentially, haven't really had a stock fan fail on me ever though), and at 60-100% it's comparable to stock running at 20-30%. But even at 100% the Noctua is more silent in my experience. Some more data points from: https://www.thingiverse.com/thing:4617648/comments#comment-5158371 Hope this helps.

@sweetdarkdestinyI was wondering if you had verified it yourself. I have seen many claim it's ~6V but haven't gotten around to checking it. It also doesn't need to move much air because the heatsink by itself is almost enough. And if you change to the slightly larger GPU heatsink there's definitely no need for a fan. Well, since you're sure, and SS_Dave is sure, I don't want to be one spreading misinformation. Unfortunately my multimeter has broken down, so I couldn't fully verify, the best I could do was an observability study and indeed it would seem to be 12V or close to it. Thanks for setting me straight!

Are you sure about this? To my knowledge the GPU fan doesn't actually receive the full 12V, it's closer to 6V as stated by op. This means it doesn't spin at full speed and you can't use a 5V fan because it will eventually fry due to over-voltage.

The shipping for the XboxHDMI from MakeMHz set me back less than USD$15 (to Finland), the actual unit is $80. Not a bad price IMO. Although given the potential customs fee I'm guessing it could set you up for a total of ~$115 (based on UK 20% VAT)? There's more info about the mod on the product page: https://makemhz.com/products/xboxhdmi and there are a lot of screenshots on the Discord if you want to get a feel of how it looks.

I wanted to switch out the stock fan for a Noctua and still retain some of the OG look and feel, this is the result. Maybe it will be of use to someone else as well. The design is up on Thingiverse and PrusaPrinters, whichever you fancy. Print instructions are there as well. Enjoy. PS. I'm also working on a design that's more compact and easier to print (in two or three parts), I'll post it if I ever get around to completing it.

OpenXeniums are pretty cheap to either build yourself or buy from someone, you should find them for ~$20. Or for about the same price you could build 5 yourself. It won't happen because it needs to be done via Xcodes meaning it happens before BFM bios/kernel initialization. You can read some more about the Xbox boot process here https://mborgerson.com/deconstructing-the-xbox-boot-rom/

I went the OSSC approach and it works perfectly fine. There's only a few settings that can/need to be changed on the OSSC but I can't remember them off the top of my head, I'll check later today. My reason for going this route was that I already had an OSSC and it was easy enough to get my hands on a YPbPr component video SCART cable from Retro Gaming Cables, so that's what I did. I tried one of those cheap component cables hooked straight to my TV and the quality was so, so bad... doesn't even come close to comparing to the high quality RGC cable. Soon I'll be installing the XboxHDMI , though .

The information needed by Insignia is read from EEPROM, so there won’t be an issue cloning the drives. Insignia also doesn't care that they share the same HDD key. Keep in mind though that some DLC may stop working when you change HDD key, so you may need to reinstall those afterwards.