Yes that was my goal with Linux to because I HATE win10. You could try this long shot but it might tell us something https://mattgadient.com/linux-dvd-images-and-how-to-for-32-bit-efi-macs-late-2006-models/ it strips out the efi part of linux to make it boot legacy only ,After reasearching yesterday i guess mac can boot in legacy mode try installing it and see what happens. Does it show up with option key? I am so surprised it didnt boot. We need to determine if its uefi or bootmngr messing it up.

Might see if this yields any info Press Command+V as your Mac boots to enter verbose mode. You’ll see the terminal messages appear during the startup process. If everything goes properly, your Mac will boot to its normal desktop.

Other than that I am dead in the water for ideas right now Since ubuntu uses grub and solus doesnt must be something with that.

    Justin Out of curiosity, why doesn't Solus use grub2 for the entire bootloader? Why 2 diff systems? (it definitely is working for Ubuntu 20.20).

        This is for my dell allinone only have solus on it the output of efibootmgr -v from what it appears dont need it if you only have one os installed, (or I am wrong) I checked and its booting in efi it just boots directly into solus fine. And I let solus set it up.:
        efibootmgr -v ouput

        BootCurrent: 0000
        Timeout: 0 seconds
        BootOrder: 0000,0004,0003,2001,2002,2003
        Boot0000* HDD1-1 (ST1000LM024 HN-M101MBB) PciRoot(0x0)/Pci(0x13,0x0)/Sata(0,0,0)/HD(1,GPT,26657955-0418-4a7b-8fc7-196db88050f4,0x40,0xf4240)RC
        Boot0003* Network BBS(128,Network,0x0)............................0..........................................
        Boot0004* Hard Drive BBS(HD,Hard Drive,0x500)................-...........!.....................................Y7v.......A.........................
        Boot2001* EFI USB Device RC
        Boot2002* EFI DVD/CDROM RC
        Boot2003* EFI Network

          Axios Thanks, this is helpful though I had set it up similar to this just with the Apple disk conventions. Will take another boo at it this weekend when I get some time. By altering the bootmanager settings I've definitely caused further install mischief on my machine. =p

            Turn off the machine when you try this turn it back on as its coming on hit f9 every 1/2 second or so see if that does anything!

            In order to maintain compatibility with MS-Windows, Apple uses a hybrid UEFI and Legacy MBR mode. Apparently, there is an NVRAM value that tells the firmware whether to attempt to boot in UEFI mode (OS-X) or in legacy MBR mode (Windows). That value is controlled by your selection in "System Preferences > Startup Disk". (Don't ask me why, ask Apple)
            I think I would seriously try the legacy solus to see if it boots. if it does would tell you theirs a problem with the efi setup

            Am done rambling let us know how it turns out this is what happens when your a tech for 30 years..haha

              6 days later

              Justin And yet, it's the only thiong that is working. I think it's grub2 actually.

                Axios Hehe. I hear you. I have about 25. I ended up bricking the machine and then completely nuking the partitions and boot manager and starting from scratch. Solus would not install despite best attempts. I am stumped as to why at this point but I was capable of getting POP_OS! 19.10 to install (I needed to disable encrypted drive as the keyboard was not supported when booted in but after that works fine.).

                I will do some digging around some more when I have more time to play with it, but I may wait for Solus to update to 4.2 =p and see how POP_OS does when it gets to the 20.04 release since it's Ubuntu and Debian based. The latest Ubuntu 20.04 nightly borked on installing (despite a previous working) so feel like maybe some patience here might be a good idea. Lol.

                I think the biggest issue here for me is not really understanding what precisely is going wrong. I will go read up a bit more about EFI nad new bootloaders and what mystic things Apple is doing differently. LIke I said, I love the hardware of the Macbook 12" 2016 but at this point, probably looking at a new LG Gram 14" when they're out in a month or so to just make life easier on myself. =]

                  That makes 2 of us I read somewhere One needed to use apples diskutil to setup partions because they did things different could do a internet recovery and use the diskutil and see if things fair better just a thought. Also I saw one guy said keep the apple boot part because it needed because way apple does things. It seems there is no one way on apples to get them working sometimes. Trial and error I guess