It's maintained as a set of patch files, so it's at least easy to see how it differs from upstream. The number of patches seemed somewhat manageable, though with the few I looked at I found myself wishing that they had much better documentation.

It's actually totally managable and reasonable for an end-user to stay on top of their patches and run a personally built subfork. I think it's better to think of it a a starting-point and template for your own builds rather than a Product.

They're reasonably tidy, not too big, and much of the size comes from a typical userprefs a la arkenfox.

I don't see why you would dissuade before even looking? This is one of those scenarios where verifying the work is a small fraction of the time and expertise to produce it.