Hi,
My understanding is that these patches are pretty much independent from each other. If so it may help a bit to not send them as a patch series, that is without the partX/total numbering. It could still be a thread for the sake of the mailing list though I don't know if that's easy to achieve.
The reason is that for patch series it has to concatenate each part with all the preceding ones. In this case this means more and more things to recompile and thus increasingly long tasks as it progresses through the series.
That said, for a series like this, most of the time is spent running the tests on Windows so it would only help a little bit. That means if not making a patch series is not practical it's ok not to.
There's no need to resend the already sent patches of course.
Also there was a question about job priority the other day on the mailing list. Notice that this job got a higher niceness that regular mailing list patches: 6 instead of 5. That's because one of its tasks had a long timeout. That mechanism still leaves a lot of room for improvement though.