I've had some success contacting postmasters of smaller orginizations and explaining to them why blacklist $x really wasn't a good one and offering some alternatives, but this method is a bit tedious and prone to failure
I do something very similar, but instead of using the company name (or something close to it) I use a long random string instead. It mainly prevents someone from 'company hopping' (i.e. changing 'facebook' to 'google'). The chance of that happening might be small, but I figure I may as well as it isn't really any more effort
I'm quite excited for this! I have a monthly data-cap at my residence and updates will often reach in to the several hundred megabytes range (sometimes even reaching 1GB!)
This would allow me to download the updates once and then spread them out, saving me a bunch of data for other things! Good on you, Microsoft.