The new (2020) TalkTalk router is possibly an easy target and has good hardware.
this tear-down says it has open source firmware, meaning porting to openwrt should be easy (as it probably already uses a openwrt derivative) https://rhyslolly.com/2020/12/12/talktalk-wifi-hub-black-huawei-dg8041w-review-test-and-tear-down/
Besides someone needing access to this hardware to try and port it, what makes you think it should be easy? When I skim your link, I'm seeing a 'Triductor VSPM340 SOC' mentioned, I've never seen support for that one on OpenWrt. Grepping the OpenWrt source code for it doesn't return anything either.
Running some stone age OpenWrt based vendor SDK != easy portability.
oh that is a shame. I have access to one if it helps. Was just thinking if it's given free with TalkTalk then it will be ubiquitous and it has good hardware, plus already is open source...
But yes, expect you are right, assumed having one version of openwrt would help porting to another, but never tried myself.
More information about VSPM340 can be found via the forum search:
If you can get one to a developer that's interested in porting it, yes, but bringing a new target (architecture) into OpenWrt takes a lot more work than adding a device using an already supported SoC.
Your firmware is not open source; the basics might be, but it's the binary blobs that basically make it tick. If you got your hands on the GPL tarball of the firmware, that would help, but even then there's still work left to do.
Furthermore this SOC isn't supported by the mainline kernel either, so any plans to support it would involve a much more uphill battle than 'just' adding a new (mainline linux supported) target (which is already rather complex). But in this case you'd have to isolate the necessary SOC support patches from Huawei's GPL source (so they exist), hope that they're complete (not missing parts of of, not linking in binary-only objects) and legal to use (explicitly GPL2 (or compatible) licensed), before forward porting them to current kernels (and ideally submitting them to mainline linux first!). Once you've mastered that, you have to keep in mind that Huawei has its own wireless chipsets as well (admitted, I haven't looking what wireless solution this device is using), which doesn't have any mainline drivers either - so you'd be starting the same endeavour for those as well.
Chances for this to happen (unless you dedicate your own time and experience to it), minimal to non-existent - there are just better/ easier devices (and targets that are at least partially supported mainline) around.
Has anyone installed OpenWrt on a DG8041W-2 T5?
Did you read the thread?
I glanced through... Having just tried the router, I see that it uses Open Source, so just wondered if that might have been OpenWrt. It's handy enough for me as it is as it gives me a WAN port as well as four LAN ports, so it will be replacing my Virgin media router up in the loft, oops study 
So, no OpenWrt support for Huawei DG8041W. Sad times :<