How can i add an exotic device

How can i add an exotic device to an existing target/subtarget ?
it is a matter of Easybox 904xDSL aka Arcadyan VGV952CJW33-E-IR it is a target=lantiq nad subtarget=xrx200 device.
But it need modified driver for RTL8367b switch, there own kernel default-config and there own kernel patches.
My Ideas:
1.) creating a new target= lantiq_vgv952cjw33-e-ir but it is crap because i must change a lot of depens inside packages.
And it is ugly
2.) changes inside makefile include to the effect that it is possible to have an extra directory for your device.
for example: target/linux/lantiq/xrx200/vgv952cjw33-e-ir in this directory are the own default-config and the ./file and patch directory like the target directory ./lantiq
But it is very difficult for me and i fear that will never accepted.

I wondering that exist no solution for this problem, because i thinking that happens from time to time.
Or i am wrong ? exist a solution ?
Exist a example device where i can do look to it ?

The work is done by Quallenauge and the other folks of this thread
But it will be cool when it get to the upstream LEDE/Openwrt.

The only solution for this would be to remodel the kernel patches in a way that all devices, normal xrx200 and your VGV952CJW33-E-IR, can be supported by the same driver. Either via auto-detection or device tree.

Adding new targets/ subtargets (which don't share the kernel with other devices of the same target) puts rather big strain on the buildbot infrastructure and should be avoided, if possible. I realize that the VGV952CJW33-E-IR is quite different compared to normal lantiq devices, but the SOC itself is the same - the problems are 'just' the different switch initialization, the non-standard ECC canary and additional features (like the display). Individually rather small differences, but a larger number of them.

This what i read from kernelpatches are not the problem because it remains the old stuff.
But i must created patches for the RTL8367b switch and the kernel default-config differ.
I fear it is not possible.