What exactly makes you think the dots problem has anything whatsoever to do with the hardware on the OP5? The dot problem is caused by poor programming on the part of One Plus and since the problem goes down to firmware level nobody can fix it but One Plus--which means it will never be fixed. One Plus has lousy programmers. There's an Oppo model that was the basis for the OP5 but it takes much better pictures. The difference is that Oppo actually spends money to attract talented software engineers while One Plus puts all its resources into hardware. One Plus programming and customer support are the worst.
You might have heard at least something about One Plus taking numerous shortcuts in their programming of Oreo which still includes a lot of Nougat code that should not be there. That has been completely downplayed on XDA but no other commercial smart phone brand would use a stock OS with such sloppy programming.

There is an aphorism about what happens when you assume.
So no, I didn't hear anything about the Oneplus, did I mention OP5 or the Oneplus?
Maybe give One Plus a call or write them an email with all of your concerns about their stock OS. Instead of veering way off topic with your opinions regarding Oneplus, and their so called "sloppy programming", "Oreo still includes Nougat code...", puts all of their resources into hardware etc.
FYI, I made the comment while using the XDA app. ( I subscribed to many forums) and admittedly I was not aware that I was in a subcategory of the Oneplus 5. But, It doesn't really matter. Because, the topic of this forum is Google Camera working HDR+ Some of us try to resolve issues by reviewing solutions for other devices. Its an educational process and the reason to subscribe threads for multiple devices.
In case you weren't aware. Quite a few people have reported issues with the Modded G-Cam while using the HDR + option. The main problem was that a grid of blue and Green dots would appear while using the HDR + option.
In some cases phones nearly identical hardware as the Pixel could only use certain features. Such as the Mi5, which has the same Sony IMX378 sensor that's in the Pixel. Some variants of Le Eco phones were shipped with an array of differing sensors. But, regardless of issues, the ported G-Cam software still greatly improved photo quality. My Le Eco X727 shipped with the pretty decent Sony IMX278. The Oneplus has the Sony IMX 398, and IMX350.
In the end, XDA Developers worked together sort out the issues with using the ported Camera with a wide range of different but similar hardware. They do not have the source code for the Hal sensor, so they build shims, that they share to give us a great experience, the basis of my original comment.