I have a semi-bricked ZBT WE3926-5G. It was running an OpenWRT build of some kind. I don't know the version, or where it came from.
Here are my questions:
Thanks!
It looks like I was wrong about it being bricked. I just didn't give it enough time to update itself.
I used this image: openwrt-19.07.1-ramips-mt7620-we1026-5g-16m-squashfs-sysupgrade.bin
I saw a web page somewhere on line that suggested that the WE1026 and WE3926 were the same. Does anyone know if that is true? ...that the WE1026 and WE3926 are the same?
The original WE3926 was the same as the WE826. Which is the same as the original WE1026.
The WE1026-5G can run the WE826 firmware but is missing the 5G Wifi.
So you can assume the WE3926-5G can run the WE1026-5G firmware without issue.
ZBT recycles a number of these routers with different model numbers and different packaging but the same internals.
Excellent.
Here is a super newbie question. (This is my first day messing with OpenWrt.) Should I expect OpenWrt to set up a WAN interface automatically on this router? Or is that something that I have to set up manually?
You seem to know much about this. So can people update and flash new firmwares on these and set it all up themselves? Any guides on that? Is the firmware closed source and locked from manufacturers when people buy these? Can you please explain a bit on how these work, and why people can't download packages? Thanks!
Because the firmware is made by the vendor, not Openwrt.
Ok.. Well, they did flash openwrt on it, so it supports openWRT. 
So it could be easy maybe to upload regular openwrt, but then people would need to set up sim cards and that could be hard to do.. All of the setting and such. Maybe the vendor can tell how to open up the code and set it up so sim card works.. People buy these because they think it's open source and good coding, not because it runs openwrt.. Both, but open source openwrt Not closed source openwrt, nobody ould use openwrt then.. Who knows what code even runs on these really.
Not blaming anyone they could be clean and secure, but who can tell if they can't even update the router.
it's probably the other way around, but if the hw is supported in general terms, it's definitely doable.
I think hell will freeze over sooner.
But these things aren't vendor specific, you can probably get it to work with or without some detective work.
This applies to pretty much all routers, doesn't it ?
No, not if it runs libre software. 
Openwrt without blobs, or librecmc, etc.. ROOter and so on.
Maybe.. I dont know how willing they are to help with that.. Its no big deal. Just software and a router
Is it hard to set up APN and a 4G router device and such on these routers if people flash a clean openwrt image? They have made it easier to use them, but limited the functions, so yeah.. Not that cool.. A router should be able to update and install openVPN or whatever if they bought a router. hmm.
Talk about a clickbait router.. "OpenWRT". People think it's open source, buys it and it's not.
Like a number of manufacturers they try to leverage on OpenWrt's reputation by using a firmware that is based on a really old version and with many modifications, most notably the use of closed source Wifi drivers. It is OpenWrt if you squint in a bad light.
Much sooner. They have never released any thing about the source code and don't want to.
I make custom OpenWrt firmware for companies that buy hundreds of ZBT routers and they don't want to help get a proper OpenWrt running on it. Everyone one of these companies universally hates the factory firmware and won't use the router if there isn't an alterative firmware available.
Totally unwilling. They even have the gall to tell people that they send new firmware to that they don't want anyone stealing their code when they use code taken from ROOter. Pretty hypocritical.
You can use a ROOter firmware for ZBT routers and it is OpenWrt with additions to handle modems in an easy way. Much better than the factory crap. .
If I would ever be in the position, where I could make any kind of influence on the procurement process for wifi hw, OpenWrt compatibility would be my no 1 must.
Hey if that's true... what formware do you think could re-flash the WE3926 with open source openwrt? If you had to pick the best flash file online? I can try it out! Mine is broke i think.. Then i can try to set up a 4g sim card. Please try and think of some flash file that might work.. Maybe some expert on this forum knows of a firmware that works even, and way to flash closed source code on those? Please tell me a way.. thanks!!
THANKS! So do you think even newer firmwares that would work? Did you just upload it on the router and it worked? I need to find the latest that works.. Not sure if it's the 3g and 4g version you write as 5g, but i think so.. It's the firmware name you meant right..
If anyone on this forum has flashed this router please do tell of ways to flash it, or link me sites that can. Thanks
Aha! That's great... What version of the ROOter firmware would i use for this model?
Please link working firmwares and ways to flash them.. Maybe just uploading them in the restore/flash tab? Thanks a bunch! Also, yeah i mean people buy it for the opensource-ness, and if it's just some selling name people get disappointed if the firmware is like 10 years old and locked of-course. hehe.. Can't even install packages.. Lame! Cant even update it! But the store that sells them says you can..
So if i can't flash this one and unlock this i will bring it back to the online store, but yeah rooter should work..
I wanna set up this router.. if they can flash it so can i.. Just need the right images, so yeah thought i ask for help. Also, how to flash it, but i guess i could just upload it in the restore tab right? If they have not also blocked that function as they have blocked upgrading packages that is..
I mean who wants old software? The hardware seems ok. Quite good it supports a sim card. But the software is bad..
When i fix that i need to set it up though and that is not the easiest, so yeah they did that, but could left it open source, still in my opinion.. No need to lock the code just because they set it up in a good way so it's easier to use..
You need to ask your questions on the ROOter forums. ROOter != OpenWrt.