After trying OpenWRT on my HooToo HT-TM01 and realizing that it's definitely not something I'd want on a device like this I now want to go back to the stock firmware again. However there are literally 0 entries anywhere on this and the guy who ported OpenWRT over to the HT-TM01 simply closed the issue on GitHub with no further comments...
Is there anyone out there with knowledge on how to go back to stock again on that thing? Would be awesome, thanks in advance!
Uhm, yeah, that's the device's page and they do have a stock firmware image there but how would one go about to flash it?
How did you flash OpenWrt?
You may need to get access to the device's boot loader, but often an OEM will describe how to flash their firmware on a soft-bricked device.
Well they sadly don't describe anything on how to unbrick this device 
Try contacting the author of the code you used through GitHub
As I said in my original post the author simply closed the issue...
You've hopefully got the link to the PR, so unless the author has deleted their GitHub repo, you should have access to it.
Well, their project is still up but the problem is that it overwrote uboot and I don't have a dump of the original firmware the device came with nor has anyone else provided someone as it seems
Bricked, unless you've got a flash programmer and a copy of enough of the flash to at least install a functional boot loader.
I saw that the guy who wrote the installer did make a backup when flashing the firmware on the device but that USB Stick is definitely long gone on my end... I wonder if I can flash someone elses backup onto mine and if it'd work then.
Have you destroyed your cal-data partition as well? If so, it may never work as it should.
I really don't know, all I did was to use the OpenWRT script/upgrade package the guy provides which then did its own magic... I have no idea what partition it changes or what exactly it does at all.
Ok, so you flashed a binary for an HT-TM02 on an HT-TM01??
I would very carefully read https://github.com/wingspinner/HooToo-Tripmate-HT-TM02-OpenWRT and hope that you've still got that stick
Useful links: OpenWRT main page http://openwrt.org OpenWRT wiki http://wiki.openwrt.org HT-TM02 thread https://forum.openwrt.org/viewtopic.php?id=53014
The TM02 with the factory software doesn't have enough RAM to untar/ungzip and assemble the complete TM02 flash MTD image for the upgrade so it requires a USB flash stick to use as workspace. So does the new loader. Having a clean USB flash stick plugged in is required.
The first thing the loader does is shutdown various services that might interfere with the flashing process and perhaps free up some RAM. Then it creates a complete backup of the factory flash MTD device written to your USB flash stick. It copys the entire TM02 MTD device as one file as well as each partition seperately to seperate files. The files are named appropriately and will be under the "HT_FLASH" directory on the stick. You can use this to revert back to factory if you wish. I'll writeup some instructions later for this.
(No wonder the PR wasn't accepted -- this device is apparently even worse than most https://openwrt.org/supported_devices/432_warning)
Well, that was years ago when I flashed OpenWRT, that stick even if I still have it has most likely been overwritten and formatted already... Oh well, guess it's game over for me then.
Did you solve your "back to stock" problem?
If not, just reach them out:
and ask for the latest Stock Firmware!
I could help if your device supports TFTP recovery and somebody has the official stock firmware upgrade zip.
I have a backup for you, @EpicLPer!
Are you still interested?
Heya! Yeah, still interested 
Would be awesome!
OK!
I'll provide a gdrive link with files for TFTP recovery in a few hours.
Until then, please setup your TFTP recovery environment!
... few hours later ...
Here are the files: backup-fw-WiFiDGRJ-HooToo-TM01-2.000.022-8850118661
I created those files with EnterRouterMode.sh
Use mtd4.bin (+ optionally mtd5.bin + mtd6.bin + mtd7.bin if it doesn't work) as kernel and mtd8.bin as rootfs for the TFTP recovery.
That's the usual "Pressing reset while powering on the device" stuff with TFTP server at 10.10.10.254.