Thanks for the feedback (and credit for the change is for MartinB not myself). The next challenge is to explain why this issue appears now (recently) and not years ago. In other words: what other change has someone done in the (u-boot/kernel) codebase to result in this being required?. Once that's been explained the upstream maintainers can think about pushing a global change to e.g. gxbb/gxl platform .dtsi files (not board level files) to fix the issue everywhere.
In the short term I'll include the patch for C2 and see if it also solves a similar (but older) issue report on WeTek Hub.