I just got an email from Karina who told me she made better icons work with Inkscape 0.92.3, too. I'm not entirely sure how she did it, but I'll tell her about this forum thread, maybe the two of you can work together (e.g. make a merge request that fixes some of the icon issues for 0.92.3 already, and/or offering a downloadable icon set for hdpi screens on the Inkscape website - 0.92.3 will be released soon, so hurry!).
I don't know if your interests align sufficiently, but it might be worth a try.
The master branch has severe performance issues on Windows - if you're not running into them, then you're quite lucky to have good hardware and small files. It's deemed unstable - but maybe Karina's solution will work for you, too. Hope she'll get back to you here.