Messing with those options seems to have given me nothing but a Recovery tab with "ROM Image update denied. EFI_NOT_FOUND! ROM Image is not loaded"

Did I do something wrong in my flash? Or are these settings just not the ones im looking for.

@Lost_N_BIOS Think I got my hands on a 5055 rom - attached it to post. Do you think it might help figure out how the tabs are hidden? (as on the 5055 model they are visible)

Sounds like you did not do the mod right for your message #16, upload that file/files for me and I will check it. Also, specify exactly what you changed and how, since I gave several suggestions and method to modify things, I am not sure what exactly you edited, so unsure what the expected outcome should have been.
I will find your edits, but I need you to explain you intended edit to me (Such as I hex edited this setting, etc), so I can check to see if it was done correctly on whatever setting. Also, show me an image of what you're seeing in BIOS
If you changed the Windows from Android settings we were discussing, I doubt you'd see any changes in BIOS, just now go and try to install windows.

On the 5055 rom, a dump from this system wont help figure out the tabs, I only mentioned this when thinking about cross-programming in this BIOS to your board
But, since we found same stuff in your BIOS no need for that anyway since we can adjust it all on your BIOS and don't have to crossflash.

Unfortunately I don't have access to the system until mid next week to take a photo as requested - but I can provide the file and the edits performed.
I just used AMIBCP to edit the values of the optimized defaults for Main->Setup->Advanced->OS/Bom Configuration:
I set the following:
OS/BOM Selection: Windows 8.X/BOM3.0
BOM Selection Switch: Development Mode
Pre-OS/BOM Selection: windows 8.X/BOM3.0

Attached is the file that I flashed.

No need for images for now then, and thanks for explaining the changes you made.
Without seeing images, and knowing what and how you edited, what you mentioned sounded like maybe bas hex edit and some BIOS failure or something, but now that you explain I get it and don't think that at all.

I would like to see this recovery tab when you have a chance to take some images though, it doesn't sound like what we can see in AMIBCP recovery tab.
And I wonder why that shows up anyway, you didn't set "Development mode" did you? I wouldn't think the OS Changes you made would invoke recovery tab options?

I'd go ahead and try to install windows now and see if you notice anything different. Depending on the other applied settings (even hidden ones), you may need to install from GPT to GPT partition, if Secure boot or UEFI Boot etc is enabled

I did pop my usb in even with the recovery screen and couldn't get it to show up in the boot options - the bios is locked down enough that I'm convinced you have to manually add the usb as a boot option through the boot menu (I believe I posted a relevant photo earlier)

Either that or the recovery stuff was blocking any form of boot..

Regardless I'll try and update you when I get my hands back on the device, it'l be a bit.

OK, I will keep trying to figure out getting that boot tab visible then. What you can do as a check, is program in that 5055 dump, and see if it shows Boot tab, if it does, then let me know, maybe from that I could figure it out, but they looked pretty similar in this area so I didn't compare too deeply when I first looked the other day.

@Lost_N_BIOS

Good news and better news.

Ordered a spare motherboard as I had a few close calls on the current one - this motherboard game with manufacturing mode 1, which exposes the boot tab. I've attached a dump of this rom in case it shows anything useful.

I also flashed the 5055 rom on to the 5050 and it exposes every menu option I wanted and immediately booted from usb! Woohoo! I consider this a working solution and have attached pictures of what that bios looks like.

Thank you for all your help up to this point - I've got something that works so I don't think we need to poke around this bios anymore, but I'm more than happy to try things if you just wanted to try and solve it anyhow.

hello, i have a 5050 with manufacturing mode and want to install windows, so it sounds like if i flash this with the 5055 bios it will work.

Can I flash this without a programmer? I can boot off usb with the current bios?

Edit: I have downloaded the bios and utility fro Dell, have anyone tried to flash this to the android hardware?

Edit2: of course can't appear to boot dos from uefi bios... so can't run the exe file