Donating your idle CPU time to the global network definitely helps! Especially right now, when a new tier of content comes out, we can use all the processing power we can get! We're working right now on cranking out new tank/healer strategies, and we are mainly limited by CPU power.
We don't have a way to donate or target specific features though -- in general we prefer to give you something you want to buy rather than accept donations.
For healing in particular, we will be adding another raid healing script based on an Antorus boss at some point, and hopefully others in the future.
Another thing to keep in mind, especially for healing but relevant for all specs: ideally we would have data for every unique boss, but the time/cost is prohibitive. So what we do instead is pick fights that are representative of a common style. For example with DPS, having one single-target boss with some realistic movement requirements is a very good approximation of any single-target boss with some movement. For healing it's the same idea: we script some situations with a common pattern that is applicable to many bosses.
Our current raid boss healing script has very high tank damage on both tanks for the entire fight, and then predictable raid-wide damage events. We want to make another one without such high tank healing requirements because it definitely changes things for a healer. But there are fights in Antorus where the high tank healing script still makes a lot of sense, e.g. Aggramar or Felhounds.
Simulating healers is a pretty new thing -- we're the only people who have done it to my knowledge. If you or people you know are interested, definitely send them our way if they have questions or doubts -- we have revised it several times based on community feedback, and it's feeling very good now.
And please don't tell people they are stupid, but please tell them that you like AMR! And definitely encourage people to turn on the global network when their computers are idle (while asleep or at work), it really helps!