I'm actually trying to find the fastboot OEM codes right now but its not as straight forward as I hoped. Using this guide:
https://www.xda-developers.com/how-to-discover-hidden-fastboot-commands/
Almost all of the original zenfones 2,4,5 got an unlock tool to unlock there bootloaders for atom clovertrail phones and i tried all of those unlockers on my asus trio tx201la also but it must have a different unlock command used in fastboot because I think those apps were simply a fastboot command wrapper. Anyway if I can find an unlock there is a chance I can flash a UEFI bios and escape to linux.
I'm sorry, however unlocking the bootloader, and getting into UEFI are two different, and completely unrelated things.
The Android bootloader is a custom fork of CoreBoot, with a custom boot implementation. That is what you are trying to unlock, as in, disable the mechanism that blocks modifications from the bootloader (aside from updating the installed image with a new image that shares the same digital signature).
Getting into UEFI, means booting into the UEFI boot implementation, which requires UEFI being already on the device, which your tablet probably does not have.
The only way to get UEFI on your tablet, would be to build it yourself, as well as a new firmware, which includes they aforementioned UEFI module (unless someone has already done it, which is unlikely), and flash it yourself (quite possibly necessitating a hardware flash, i.e. using a dedicated programmer, such as the CH341A (readily found on AliExpress), to flash the new firmware directly to the required chip on the board (usually an SPI chip, though on an Android tablet, it may very well be the same NAND chip that the OS is installed to, which complicates things as to how OSs will be installed later).
So don't give up, however take things one step at a time.
First unlock the bootloader, then try building for it a new recovery (preferably TWRP, though CWM may be easier), then compiling for it a new kernel, and after that, porting a new ROM to it.
You do not have to do this in the above order, you can jump directly to compiling a new firmware for your tablet, however only after you have enough experience, do I recommend you to try messing with alternative firmwares.
